tag:blogger.com,1999:blog-78051742024-02-20T01:36:29.592-08:00AMacAMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.comBlogger25125tag:blogger.com,1999:blog-7805174.post-82733796374895856042020-12-01T06:42:00.166-08:002020-12-01T07:31:21.645-08:00Comment on the Substack post "Anomalies in Vote Counts and Their Effects on Election 2020"[Note: I originally wrote this as a Comment for the Substack post, but the comments section for that article is a train wreck. So I am putting it here, as a new post on this dormant blog, which I started to record thoughts on a technical issue in Holocene climate reconstruction. It is exceptionally difficult to fish out information from the good Substack comments, so this is disappointingly incomplete. But I am out of time. Maybe I'll edit/improve it later. --AMac78]<p>
On 11/24/20, the pseudonymous "Vote Integrity" posted <a href="https://votepatternanalysis.substack.com/p/voting-anomalies-2020">"Anomalies in Vote Counts and Their Effects on Election 2020: <i>A Quantitative Analysis of Decisive Vote Updates in Michigan, Wisconsin, and Georgia on and after Election Night</i>"</a>.<p>
The author designed and employed a method to highlight unusual and possibly fraudulent additions to the vote counts in battleground states. To do this, he or she advantage of <a href="https://www.edisonresearch.com/election-polling/#two">the time-series data that Edison Research created</a> for each of the 50 states for "National Election Pool" subscribers, and that the <i>New York Times</i> posted online.<p>
Two excellent tools:<p>
* Substack commenter Steve created a script that pulls the Edison data and generates time-series graphs (like the author's Fig. 1/Michigan and Fig. 2/Wisconsin) for the state of your choice, <a href="https://hallys.net/votes/">at this page</a>.<p>
* Substack commenter Mario Delgado coded a self-service application that uses the same source to generate anomaly profiles (like the author's Fig. 3/Michigan and Fig. 5/Wisconsin) for the state of your choice, <a href="https://observablehq.com/@mariodelgadosr/2020-presidential-election-time-series-anomalies">here</a>.<p>
The author uses statistical procedures that identify "anomalous" batches of votes that were added to the State Election Boards' running counts, beginning when the polls closed on the evening of Tuesday, Nov. 3, and continuing for the next few days. The core assumption is that the voters of each state are evenly distributed. In other words, each subset (precinct - city - county) has more-or-less the same percentage of Biden and Trump voters. In addition, Biden and Trump voters would be more-or-less equally inclined to vote in person or by mail... and so forth.<p>
The author isn't stupid, s/he <i>knows</i> that these assumptions aren't completely true. This is taken as a starting point to find possible needles (phony votes) in a haystack of genuine returns.<p>
Readers who are unfamiliar with the field should be aware that there have been multiple informed criticisms of this approach by commenters who are very knowledgable in statistics and forensics. Thus, my advice is to be very wary of accepting the author's methods and conclusions, without considering the merits of those critiques. I raise this as a warning -- that subject is beyond the scope of this comment. And, unfortunately, sorting through thousands of Substack comments to find these solid criticisms would be a major chore.<p>
In the section "Quantifying the Extremity," the author presents a table with ten anomalies -- suspicious batches of votes that were added to the Presidential race's tallies, late on Election Day or in the early morning hours of the following day. S/he highlights (in yellow) these four entries from battleground states:<p>
Anomaly 1. Michigan batch on 11/4/20 at 6:31AM EST -- 141,258 Biden / 5,968 Trump<p>
Anomaly 2. Wisconsin batch on 11/4/20 at 3:42AM CST -- 143,379 Biden / 25,163 Trump<p>
Anomaly 3. Georgia batch on 11/4/20 at 1:34AM EST -- 136,155 Biden / 29,115 Trump<p>
Anomaly 4. Michigan batch on 11/4/20 at 3:50AM EST -- 54,497 Biden / 4,718 Trump<p>
As of this writing (12/1/20 1430 GMT), the comments to "Anomalies in Vote Counts..." have provided strong evidence that:<p>
* Anomaly 1 is explained by the City of Detroit's report of most of its Absentee ballots to the <a href="https://www.michigan.gov/sos/0,4670,7-127-1633_8722-103241--,00.html">Michigan Secretary of State</a>.<p>
* Anomaly 2 is explained by Milwaukee's report of most if its Absentee ballots to the <a href="https://elections.wi.gov/node/7239">Wisconsin Elections Commission</a>.<p>
I don't know if other commenters have explained Anomalies 3 or 4.<p>
I've written up this summary because the Substack commenting system as adopted by "Vote Integrity" fails to support an informed discussion of the points raised in the original article. As far as I can tell, submitted comments are impossible to search, and nearly impossible to link effectively. So the most civil and informative remarks get buried, and people new to the post never see them. Discussion doesn't build on what has been linked, discovered, and discussed. Instead, amnesia rules the thread. Hard-won insights on technical issues are overlooked, forgotten or ignored. As a result, everything keeps getting re-litigated from the beginning. Tempers fray.<p>
<b>Anomaly 1. Michigan batch on 11/4/20 at 6:31AM EST</b><p>
The City of Detroit published the PDF "November 2020 Election Summary Report Signed Copy" on its <a href="https://detroitmi.gov/document/november-3-2020-general-election-official-results">November 3, 2020 General Election Official Results page</a><p>. Page 2 breaks down election results, 100% of 637 precincts reporting.<p>
74,733 Election Day and 166,203 Absentee votes for Biden<p>
6,736 Election Day and 6,153 Absentee votes for Trump<p>
1,126 Election Day and 1,081 Absentee votes for Other candidates<p>
(also 373 Election Day and 109 Absentee unresolved write-ins)<p>
Anomaly 1 is 141,258 Biden / 5,968 Trump / 2,546 Other thus 94.3% / 4.0% / 1.7%<p>
Detroit City Absentee is 166,203 Biden / 6,153 Trump / 1,081 Other thus 95.8% / 3.5% / 0.6%<p>
Commenter "Mike" linked sources that showed that Detroit counted its own absentee ballots, and submitted them directly to the State -- they were not consolidated with absentee ballots from the other jurisdictions in Wayne County.<p>
<b>Anomaly 2. Wisconsin batch on 11/4/20 at 3:42AM CST</b><p>
<a href="https://elections.wi.gov/node/7239">Page with downloadable Wisconsin vote data, by county</a>.<p>
Milwaukee City (pop. 590,000) is one of 19 municipalities in Milwaukee County (946,000). <a href="https://county.milwaukee.gov/EN/County-Clerk/Off-Nav/Election-Results/Election-Results-Fall-2020">This County government page</a> says the City recorded 169,519 absentee ballots. I don't see a total for the County total. It looks like the municipalities report to the County, which then reports to the Wisconsin Elections Commission (is that right?). But without a breakdown of Biden and Trump counts for absentee ballots, it's going to be impossible to a detailed comparison of the Milwaukee submission with Anomaly 2.<p>
<a href="https://www.jsonline.com/story/news/politics/elections/2020/11/04/wisconsin-results-down-wire-again-milwaukee-ballot-count/6123344002/">Milwaukee Journal Sentinel article of 11/4/20</a>, "Biden overtook Trump in the early morning hours when Milwaukee reported its roughly 170,000 absentee votes, which were overwhelmingly Democratic."<p>
Commenter "Eric 377" wrote on 11/29/20: "I live in Wisconsin... My understanding is that update [listed by 'Vote Integrity', i.e. Anomaly 2] is Milwaukee County data. Milwaukee County is the state's most populous and easily the highest number of votes cast, yet the elections staff is proportionally not smaller than other counties. Prior to the election, the Milwaukee media reported that the elections team was very well prepared, but the size of the team, their resources including numbers of voting machines and the vote totals tell us that their actual performance was the worst in the state, and by a lot, compared with other counties with similar 'per vote' resources... It seems to me that the most 'acceptable' rationale for Milwaukee being hours behind where they were expected to be would be exactly that the team was a lot less efficient than teams in the rest of the state. The second largest county in the state, Dane (also the second greatest source of Biden votes) reported nearly 100% of their votes almost 6 hours earlier than Milwaukee."<p>
<b>Conclusion</b><p>
As mentioned at the onset, I'm posting this to serve as a point of reference for commenters at "Vote Integrity's" Substack article. New readers should be aware that Anomalies 1 and 2 are likely explained by ordinary vote-counting mechanisms. That means they <i>aren't</i> telltales of, say, a hacker injecting tens of thousands of phantom votes into the Michigan or Wisconsin vote-counting systems.<p>
I may or may not edit the post further, depending on how much more time I can afford to sink into this hobby.AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com0tag:blogger.com,1999:blog-7805174.post-57066029419004101202011-08-14T11:11:00.000-07:002011-08-15T07:53:42.080-07:00Lightsum and Darksum are Calculated, not MeasuredIn last year's post <a href="http://amac1.blogspot.com/2010/08/tiljander-data-series-data-and-graphs.html">The Tiljander Data Series: Data and Graphs</a>, I explained that the <i>four</i> Tiljander data series were actually <i>three</i>: Darksum is calculated as (Thickness minus Lightsum).<br />
<br />
I've since discovered that there are actually <i>two</i> Tiljander data series rather than <i>four</i>.<br />
<br />
Thickness and XRD are <i>measured</i> values.<br />
<br />
Lightsum and Darksum are values that Tiljander et al. <i>calculated</i> by multiplying Thickness and XRD.<br />
<br />
Here are the formulas. Varve thicknesses are measured in microns (thousandths of a millimeter, um). <br />
<br />
<b>Lightsum = Thickness * XRD * 0.003937</b><br />
<br />
<b>Darksum = Thickness * ( 1 - ( XRD * 0.003937 ))</b><br />
<br />
Solving these two equations for Thickness yields<br />
<br />
<b>Thickness = Lightsum + Darksum</b><br />
<br />
The calculated values of Lightsum are within 0.01% of the values <a href="http://www.ncdc.noaa.gov/paleo/pubs/pcn/pcn-proxy.html">archived at NCDC</a>. For Darksum, the calculated values are consistently 0.5% to 0.8% too low. Presumably, this is a rounding error.<br />
<br />
[<b>UPDATE</b> Aug 15, 2011 -- Commenter HaroldW <a href="http://amac1.blogspot.com/2011/08/lightsum-and-darksum-are-calculated-not.html?showComment=1313383483005#c5990859389396259991">figured out</a> the <i>exact</i> formulas by which Lightsum and Darksum are calculated. It strongly suggests that Tiljander et al. made a minor arithmetic error in their formulae, such that <br />
<br />
<b>Thickness = Lightsum + (( 255/254 ) * Darksum )</b><br />
<br />
"Exact" means that the calculated values of LS and DS agree with the archived values to within 0.001%. I've updated the Excel file at BitBucket to reflect HaroldW's insight.]<br />
<br />
"Discovered" as used above is tongue-in-cheek. Obviously, the authors of Tiljander03 have known from the outset that this was their procedure. However, this finding is new to me. Presumably, it is also news to the authors of Mann08, Mann09, Kaufman09, and to other people who take an interest in paleoclimate reconstructions.<br />
<br />
"Does it matter?" From a statistical point of view, <i>yes, it does</i>. <br />
<a name='more'></a><br />
Before going into <i>why</i> it's important, here are comparisons of Downloaded versus Calculated Lightsum and Darksum. Clearly, the Calculated series are essentially identical to the series as they were archived. (Graphed data available for download as Excel file <i>Tiljander03-Calculated_LS+DS.xls</i> <a href="https://bitbucket.org/amac/tiljander-proxy-graphs/downloads#download-37695">at BitBucket</a>.) The two graphs are followed by a description of the methods used by Mia Tiljander and her colleagues.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCwURTSHfTk7qf76Xdngo8TvvXSnHEBIHNZHuCkwl4-NX6-ab6-dpPyT-mRqpI3y0Imz8p0ba6wJ7clo9JyetF-DRQ7LVDqU2EHQjGg7l8gNvevY9AoNAlUpiPkeTLFDJ0ho_plA/s1600/LS_download_vs_calculated.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="283" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCwURTSHfTk7qf76Xdngo8TvvXSnHEBIHNZHuCkwl4-NX6-ab6-dpPyT-mRqpI3y0Imz8p0ba6wJ7clo9JyetF-DRQ7LVDqU2EHQjGg7l8gNvevY9AoNAlUpiPkeTLFDJ0ho_plA/s640/LS_download_vs_calculated.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2K4NLOvCezRSyEP5UTBJoaf8v3dOEK216Q9aZE4TM87G-x39vDgOrdQ58B9iAjbKe29ZSuIBwGmBeewd04WRqQAH32Cza3OkTtCFkODDMVn1HI5EHXO3OS6Hvmahw_uQcaGuslQ/s1600/DS_download_vs_calculated.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="283" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2K4NLOvCezRSyEP5UTBJoaf8v3dOEK216Q9aZE4TM87G-x39vDgOrdQ58B9iAjbKe29ZSuIBwGmBeewd04WRqQAH32Cza3OkTtCFkODDMVn1HI5EHXO3OS6Hvmahw_uQcaGuslQ/s640/DS_download_vs_calculated.jpg" width="640" /></a></div><br />
Tiljander et al.'s methods led to the measurement of Thickness and XRD. In their fieldwork, they recovered drill cores of thousands of years of varved sediments from the bottom of Lake Korttajarvi. Back in the lab, they stabilized and preserved these cores by a set of procedures that are commonly used for biological specimens. First they infused the waterlogged mud with acetone. Once all the water was removed, they then impregnated the mud with liquid epoxy, which hardened as it cured. Once solidified, the cores could be cut with a bandsaw to yield a specimen with the desired 2-millimeter thickness. (Reference: Tiljander, Ojalaa, Saarinena, & Snowball, 2002; <a href="http://www.sciencedirect.com/science/article/pii/S1040618201000684">abstract</a>.)<br />
<br />
The first analytical step was to determine the thickness of each annual varve, likely with a caliper.<br />
<br />
Second, the epoxied core segments were placed atop X-Ray film, and a pre-determined burst of X-Rays illuminated the specimen. As with dental X-Rays, some materials absorb more X-Rays than do others, exposing the film less, or more. After development, the X-Ray film was scanned and digitized. Minerals (e.g. silica) absorb <i>more</i> X-Rays, leaving the underlying film relatively less exposed. Organic matter absorb <i>less</i> of the X-Ray energy, causing the underlying film to be relatively more exposed. Thus, high XRD is indicative of a high proportion of mineral matter; low XRD indicates a high proportion of organic matter. <br />
<br />
The final step in calculating how much mineral matter and how much organic matter was deposited at the bottom of Lake Korttajarvi each year is to combine the Thickness and XRD information. The thicker the varve, the greater the total of Mineral matter plus Organic matter. The less-exposed the X-Ray film underlying a varve, the higher that varve's X-Ray Density, and the higher its proportion of Mineral matter. (And, the lower its proportion of Organic matter.)<br />
<br />
The equations for Lightsum and Darksum near the top of this post represent these relationships quantitatively.<br />
<br />
These procedures are well-described in publications by co-authors of Tiljander03. For example, on page 20 of his 2001 PhD dissertation (<a href="http://www.blogger.com/arkisto.gsf.fi/ej/ej41.pdf">1 MB PDF</a>), Antti E.K. Ojala wrote:<br />
<blockquote>our general procedure (Papers III; IV; V) has been to digitise X-ray radiographs with 1000 dpi optical resolution, providing an average of approximately 24 grey-scale data points per one 0.6 mm thick varve... The acquisition of comparable high-quality grey-scale images of the varved section is usually the most critical and time-consuming phase in digital image analysis. Owing to the considerable density difference between a minerogenic spring lamina and organic matter deposited during the summer, autumn and winter, X-ray radiography is an important and useful tool in documenting thinly (< 1 mm) laminated clastic-organic varves. Dense minerogenic layers have a greater ability to absorb X-rays than organic layers, therefore showing a lighter shadow in the X-ray film (Fig. 3). By using a 19-step standard glass sample with known density (Bresson & Moran, 1998), the comparability of the X-ray radiographs (grey-scale) of 2 mm thick slabs of embedded sediment was facilitated (Paper III).</blockquote><br />
So: <i>why</i> does it matter that two of the Lake Korttajarvi data series are calculated from the measured values of the other two?<br />
<br />
The answer lies in the idea of <i>Degrees of Freedom</i>. <br />
<br />
From <a href="http://en.wikipedia.org/wiki/Degrees_of_freedom_%28statistics%29">Wikipedia's entry</a>, here is one definition of the concept:<br />
<blockquote>A common way to think of degrees of freedom is as the number of independent pieces of information available to estimate another piece of information. More concretely, the number of degrees of freedom is the number of independent observations in a sample of data that are available to estimate a parameter of the population from which that sample is drawn.</blockquote>Think of it this way: suppose I wished to use a set of <i>proxies</i> to estimate a time series of something. That 'something' could be anything: temperature, precipitation, or kangaroo population, for instance. Since my proxies are noisy, I'll have more confidence in an estimate that is derived from a larger number of proxies -- all things being equal. But suppose I decided to increase the proxy count by copying-and-pasting columns in an Excel spreadsheet. One proxy can become two! Two can become four!<br />
<br />
Obviously, this sort of copy-paste activity can't improve my results, because I haven't increased the number of <i>independent</i> observations in the data I am using to estimate the parameter of interest (temperature/precipitation/kangaroos). In other words: bigger spreadsheet, but unchanged degrees of freedom.<br />
<br />
Returning to Tiljander-in-Mann08: <br />
<br />
If Lightsum and Darksum are used as "proxies," then Thickness and XRD <i>cannot be used</i> without specifically reducing the d.f. in all calculations -- they aren't independent.<br />
<br />
Conversely, if Thickness and XRD are used as "proxies," then Lightsum and Darksum <i>cannot be used</i> without specifically reducing the d.f. in all calculations -- same reasoning.<br />
<br />
There are two possible results if these cautions are not observed. First, the Tiljander data series will be overweighted -- there seems to be twice as much independent data from Lake Korttajarvi as is actually the case. Second, confidence intervals will be drawn too narrowly, as degrees of freedom always enter into such calculations. <i>How much</i> overweighting? Since <i>none</i> of the Tiljander data series can be directly calibrated to the instrumental temperature record -- Mann08's sole approach -- that question can't be answered. (As discussed in other posts, the proper weighting of the Tiljander data series is "zero".) <i>How much</i> underestimation of confidence intervals? There doesn't seem to be a clear answer to this question, either, for the same reason.<br />
<br />
In my opinion, there's no evidence and no likelihood of any intent to cut statistical corners by the authors of Mann08 or Mann09. The simple and obvious explanation is inadequate due diligence. This appears to be a common shortcoming of the "proxyhopper" approach favored by these and other researchers engaged in paleotemperature reconstruction.AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com13tag:blogger.com,1999:blog-7805174.post-4191790379140149742011-07-10T11:06:00.000-07:002011-12-16T13:13:27.728-08:00Pattern RecognitionScientists pride themselves in the ability to tease informative patterns out of masses of data. And with good reason -- that skill (or aptitude) is one of the traits that leads to insight, and thus publications and professional success.<br />
I don't believe that gazing at "spaghetti graph" reconstructions is the best way to evaluate whether or not the Tiljander data series were used correctly in Mann08 (for links to referred-to papers and posts, see <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html">here</a>). That's a question that's better answered by reading her paper (Tiljander03), getting a feel of what her data looks like (graphs <a href="http://amac1.blogspot.com/2010/08/tiljander-data-series-data-and-graphs.html">here</a>), and thinking about the physical meaning of the varve characteristics that go into "XRD," "lightsum," "darksum," and "thickness."<br />
<br />
By weaving these threads together, we can figure out the solution to this puzzle:<br />
<br />
<i>Can the Tiljander data series be meaningfully calibrated to the instrumental temperature record, 1850-1995?</i><br />
<br />
The answer is <b>No</b>.<br />
<br />
There might be a way to <i>indirectly</i> achieve such a calibration, which was the approach that authors of Kaufman09 took with XRD after belatedly coming to grips with this problem. But there's no feasible <i>direct</i> approach, of the type used in Mann08 and Mann09.<br />
<br />
This has proven to be a very contentious point. But there's no good reason it should be seen as such. Truly contentious questions have strong arguments on each side of the issue. The defenders of Mann08 don't even argue for "Yes," but rather for a stance akin to "I don't know, and it doesn't matter." <br />
<br />
That's silly.<br />
<br />
Knowing that the Tiljander data series were massively contaminated by non-climate signals in the 19th and 20th centuries, we can look for patterns in the reconstructions presented in Mann08 and Mann09.<br />
<br />
Let's consider a few cartoons.<br />
<a name='more'></a><br />
In this post, I will present the general case of a multiproxy reconstruction that runs from 500 through 1849. It could be anything -- temperature, precipitation, kangaroo population over time. What matters for this exercise is that we have three collections of data series that we are using as proxies for the information we are trying to reconstruct.<br />
<br />
<b>TR</b> -- This is the large, established data set. We don't <i>know</i> these series are good proxies, but overall, we're pretty confident that they are. For temp recons, think "Tree-Rings" (dendro).<br />
<br />
<b>ND</b> -- This is a new, smaller data set, of different types of series than comprise data set TR. We <i>hope</i> these series will be good proxies. For temp recons, think "Non-Dendro."<br />
<br />
Data set ND has two parts: NDm and NDk. <br />
<br />
<b>NDm</b> is comprised of most of the ND data set. In fact, it included <i>everything</i> in ND data set <i>except</i> NDk.<br />
<br />
<b>NDk</b> is a single ND series. When first encountered, it seemed promising. But it was then established that NDk is contaminated. It can't contribute any real information to any reconstruction. For temp recons, think of the Korttajarvi (Tiljander) varve records.<br />
<br />
Now, let's look at some multiproxy reconstructions.<br />
<br />
First, here's the recon built on dataset TR (shown in Black). We <i>think</i> this is accurate, to the extent signified by the error range that we calculate (not shown).<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6z0HsUnrvgPFhYAB7BmfvobjV-4F_42G0hV9EutvPcBcI9dU90i_lxTXqqPROtwaMH4z5RJR7M5Wx2QoW_GBTNrbcPbzY_K8Vj5q_Q7kYJljQOp14lk_AmjcpuJPE5KJj_f0ZaQ/s1600/TR-pseudo-recon.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="171" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh6z0HsUnrvgPFhYAB7BmfvobjV-4F_42G0hV9EutvPcBcI9dU90i_lxTXqqPROtwaMH4z5RJR7M5Wx2QoW_GBTNrbcPbzY_K8Vj5q_Q7kYJljQOp14lk_AmjcpuJPE5KJj_f0ZaQ/s400/TR-pseudo-recon.jpg" width="400" /></a></div><br />
Here's the recon built on dataset ND (Blue; dataset TR shown in Gray for comparison). It's encouraging -- it looks like the "hindcast" produced by TR is in line with the one produced by ND.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEguMrbmusxt-YiVSCUoU3Rh3iVHbgiGlkebC1hy-uaPOMFUd86OIRookXk63l88uMT7K4qArFkHI59Ow6eHPTGLC2VvCIS-3BqCvgQmAx4shCB4H2tSSfAwBj9KKtyJk3BNdv7aTA/s1600/ND-pseudo-recon.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="171" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEguMrbmusxt-YiVSCUoU3Rh3iVHbgiGlkebC1hy-uaPOMFUd86OIRookXk63l88uMT7K4qArFkHI59Ow6eHPTGLC2VvCIS-3BqCvgQmAx4shCB4H2tSSfAwBj9KKtyJk3BNdv7aTA/s400/ND-pseudo-recon.jpg" width="400" /></a></div><br />
Here's the recon built with the combined TR and ND data sets (Red). Again, this is encouraging with respect to the mental model we are working from.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8XE-_PBu0VLJaVM7vJh8IJ8kQmRzDA1cP0YvNnzuOaGu-GN6nl5yad03OoB0JJ4RjvysTtNuOVI479akQZ9rBp0D8D-Y3blcOoKt-duUy_tI0V-7P1CWjsB1yF1-H-z3YmhzD-w/s1600/TR%252BND-pseudo-recon.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="171" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8XE-_PBu0VLJaVM7vJh8IJ8kQmRzDA1cP0YvNnzuOaGu-GN6nl5yad03OoB0JJ4RjvysTtNuOVI479akQZ9rBp0D8D-Y3blcOoKt-duUy_tI0V-7P1CWjsB1yF1-H-z3YmhzD-w/s400/TR%252BND-pseudo-recon.jpg" width="400" /></a></div><br />
Next, let us <i>discard</i> the part of the ND data set that we <i>know</i> is bad. That is series NDk. The remaining ND data set is "NDm." Here's the recon built from the TR data set and the NDm data set (TR+NDm shown in Brown). It looks a lot like the TR data set alone.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_m4D61Ig20Se33QUGccRRICnBdAu6-RaKgzYtaDqbcLB_ysr7cECvhC4_VLi0MX3vHN77sTZEWKAMUgBfGKr7rYjLKHUIPlwB9GOo3YQe7scMHyeVawhmOk6lSwKyfWDEg_CbaQ/s1600/TR%252BNDm-pseudo-recon.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="171" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_m4D61Ig20Se33QUGccRRICnBdAu6-RaKgzYtaDqbcLB_ysr7cECvhC4_VLi0MX3vHN77sTZEWKAMUgBfGKr7rYjLKHUIPlwB9GOo3YQe7scMHyeVawhmOk6lSwKyfWDEg_CbaQ/s400/TR%252BNDm-pseudo-recon.jpg" width="400" /></a></div><br />
Finally, let's look at one more recon. Here's one built from NDm series alone (Green). <br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiW56kvFpllL759ERWiAwrof1kg-8CZ14dsfKSYfE9-fY7cEqJDJGKMqo_LhTNqV52QFGIgm4UzlZ_rK2_x8ph_EwvKP0T4Pds9nNK6BDzQNucTBb4sp5hgDsp3yDHV-K8IcSIMFw/s1600/NDm-pseudo-recon.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="171" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiW56kvFpllL759ERWiAwrof1kg-8CZ14dsfKSYfE9-fY7cEqJDJGKMqo_LhTNqV52QFGIgm4UzlZ_rK2_x8ph_EwvKP0T4Pds9nNK6BDzQNucTBb4sp5hgDsp3yDHV-K8IcSIMFw/s400/NDm-pseudo-recon.jpg" width="400" /></a></div>There's something funny going on. This NDm recon doesn't look <i>anything</i> like the others!<br />
<br />
<u><b>Summary</b>.</u><br />
<br />
So these are the patterns we are encountering.<br />
<ul><li>TR recon -- The recon we started off <i>thinking</i> is a good representation of the past.</li>
</ul><ul><li>ND recon -- Similar to TR.</li>
</ul><ul><li>TR + ND recon -- Very similar to TR.</li>
</ul><ul><li>TR + NDm recon -- Very similar to TR.</li>
</ul><ul><li>NDm recon -- Different from TR.</li>
</ul>The "secret sauce" that makes the ND reconstruction look like the TR reconstruction is the contaminated NDk data series. Taken together, the "legitimate" ND proxies generate a lousy recon (NDm).<br />
<br />
However, add those same NDm data sets to the TR data set, and create a nice-looking recon (TR + NDm).<br />
<br />
What we see is explained by these rules:<br />
<ul><li>Use the TR data sets, and get the TR recon.</li>
<li>Use the NDm data set, and get a very different recon.</li>
<li>Combine the NDm data set with the TR data set, and get the TR recon.</li>
<li>Add the contaminated NDk series to NDm, and get the TR recon.</li>
<li>Add the contaminated NDk series to NDm and TR, and get the TR recon.</li>
</ul>The NDm data series are a flop. But there seems to be something "magical" about both TR and NDk. Add either or both, and a TR-like recon appears!<br />
<br />
What is the basis for this magic?<br />
<br />
<br />
[<b>UPDATE</b>, Dec. 16, 2011 -- In the following comment on a recent <i>Climate Audit</i> thread, I describe this pattern from another perspective. Slightly modifed from the original.]<br />
<blockquote>AMac Posted <a href="http://climateaudit.org/2011/12/13/ar5-and-mikes-pnas-trick/#comment-316442">Dec 15, 2011 at 10:09 AM</a><br />
<br />
Comparisons of reconstructions built from tree-ring proxies with those built from non-dendro proxies can be quite difficult. This is partly because the patterns are non-intuitive, and partly because the figures in top-tier papers such as Mann08 and Mann09 are confusing, even to the point of being misleading.<br />
<br />
Here is the key observation. The addition of the uncalibratable, upside-down Tiljander data series to a multiproxy reconstruction often has effects as follows:<br />
<br />
* (A) If the No-Tiljander multiproxy recon already had the “hockey stick” shape, the With-Tiljander version will be largely unchanged.<br />
<br />
* (B) If the No-Tiljander multiproxy recon did <i>not</i> have a “hockey stick” shape, the With-Tiljander version will be changed so that it has a “hockey stick” shape.<br />
<br />
* (C) If the No-Tiljander multiproxy recon did <i>not</i> have a “hockey stick” shape and fails certain “validation” tests, the With-Tiljander version with a “hockey stick” shape will “pass” those tests.<br />
<br />
Points (B) and (C) are best illustrated by a figure that clearly shows the relevant pair of reconstructions. Such figures are absent from Mann08 and Mann09.</blockquote>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com9tag:blogger.com,1999:blog-7805174.post-69018089005833857922011-06-23T22:41:00.000-07:002011-07-06T15:20:48.675-07:00Voldemort's Question<u><i>Updated June 25 & 26, 2011 -- see end of post</i></u><br />
<br />
<i>Are the Tiljander proxies calibratable to the instrumental temperature record, 1850-1995?</i><br />
<br />
Reader Alex Harvey copied his submission to <i>RealClimate.org</i> as a <a href="http://amac1.blogspot.com/2011/06/tiljander-data-series-appear-again-this.html?showComment=1308840685683#c5927606493424585932">comment</a> to the just-prior post at this blog, "The Tiljander Data Series Appear Again, This Time in a Sea-Level Study." Some time later, it was allowed into <i>RealClimate's</i> "2000 Years of Sea Level" at <a href="http://www.realclimate.org/index.php/archives/2011/06/2000-years-of-sea-level/comment-page-1/#comment-209072">position 22</a>. The second of Harvey's two points concerned the use of Tiljander:<br />
<blockquote><span style="color: #274e13;">The study has also been criticised on various blogs for using “one of the multiproxy reconstructions that employed the <strike>four (actually three) uncalibratable</strike></span> <span style="color: #660000;"><b>[edit]</b></span> <span style="color: #274e13;">Tiljander lakebed sediment data series” <strike>e.g. http://amac1.blogspot.com/2011/06/tiljander-data-series-appear-again-this.html.</strike></span><span style="color: #660000;"><b>[edit]</b></span>.</blockquote><i>RealClimate's</i> moderators snipped the comment as shown.<br />
<br />
Prof. Mann offered this inline commentary --<br />
<blockquote><span style="color: #660000;">[Response: No. Just more of the usual deception from dishonest mud-slingers. More on that in short order. -Mike]</span></blockquote><a name='more'></a>In short order, Update 2 appeared (<a href="http://www.realclimate.org/index.php/archives/2011/06/2000-years-of-sea-level/">link</a>). <strike>Scroll down at <a href="http://www.realclimate.org/index.php/archives/2011/06/2000-years-of-sea-level/">this link to the RC post</a> for its embedded links</strike> <i>(Update: embedded links added</i>). <br />
<blockquote><span style="color: #660000;">People have asked whether the use of the Tiljander proxies in the <a href="http://www.meteo.psu.edu/%7Emann/shared/articles/MannetalPNAS08.pdf">Mann et al (2008)</a> EIV surface temperature reconstructions matters for the conclusions of this or any related studies. </span></blockquote>Wrong. "People" (me) have been asking a different question for <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/#comment-7537">over a year</a>:<br />
<br />
<i>Are the Tiljander proxies calibratable to the instrumental temperature record, 1850-1995?</i><br />
<br />
Prof. Mann continues:<br />
<blockquote><span style="color: #660000;">The answer, as provided previously in the literature (see <a href="http://www.meteo.psu.edu/%7Emann/shared/articles/MMReplyPNAS09.pdf">this reply</a> to a comment in PNAS) is no.</span></blockquote>A one-word answer to <a href="http://amac1.blogspot.com/2011/06/tiljander-data-series-appear-again-this.html?showComment=1308845994912#c1701918469666758894">an undefined, postmodern question</a>. Who knows what it means.<br />
<blockquote><span style="color: #660000;">The impact of whether or not these proxies are used was demonstrated to be minimal for the Northern Hemisphere land+ocean EIV reconstruction featured in Mann et al (2008) [see Figure S7b of the <a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxyMeans07/">Supplementary Information</a> of that article, which compares the reconstruction both with and without 7 potential 'problem proxies', that include the Tiljander proxies; a similar comparison was also made in Figure S8 of the <a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxySpatial09/">Supplementary Information</a> for the followup article by <a href="http://www.meteo.psu.edu/%7Emann/shared/articles/MannetalScience09.pdf">Mann et al (2009)</a>].</span></blockquote>I have discussed the figures of Mann08's S.I. at this blog and elsewhere. Prof. Mann again invites the reader to puzzle out just how the linked versions of SI figures might support sweeping and vague claims. Not tonight.<br />
<blockquote><span style="color: #660000;">The same holds for the specific global mean EIV temperature reconstruction used in the present study as shown in the graph below (interestingly, eliminating the proxies in question actually makes the reconstruction overall slightly <em>cooler</em> prior to AD 1000, which–as noted in the article–would actually bring the semi-empirical sea level estimate into <em>closer</em> agreement with the sea level reconstruction prior to AD 1000).</span></blockquote>These 191 dense words were followed by a new spaghetti graph.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_-mV3UV1-P26dhLlcdcdxHrPdOHsTKiGGmdUGS1NCnOaIqgwHUWokpiYBj9BMzNJqzRDGgmPCqtB0LOlhjfAXviMiWnQA6Ly8bkAcZ3fg6AZbZ96thmWcZ3lojq3B4-dDmy3-nQ/s1600/Mann08+global+EIV+recon+20yr+smooth.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="310" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_-mV3UV1-P26dhLlcdcdxHrPdOHsTKiGGmdUGS1NCnOaIqgwHUWokpiYBj9BMzNJqzRDGgmPCqtB0LOlhjfAXviMiWnQA6Ly8bkAcZ3fg6AZbZ96thmWcZ3lojq3B4-dDmy3-nQ/s400/Mann08+global+EIV+recon+20yr+smooth.jpg" width="400" /></a></div> Two variations of a smoothed "Mann et al (2008) global mean (land+ocean) temperature reconstruction" were presented, with (blue line) and without (red line) 7 proxy records (including the Tiljander data series).<br />
<br />
The graph is virtually useless.<br />
<ul><li>No uncertainty intervals are shown for either of the two curves.</li>
<li>There's no mention of which portions of the two traces pass the "validation test" described in Mann et al (2009), at the 95% or higher level. Recall Gavin Schmidt's remarks on the closely-related Northern Hemisphere reconstruction: "<span style="color: #660000;">...it's worth pointing out that validation for the no-dendro/no-Tilj is quite sensitive to the required significance, for EIV NH Land+Ocean it goes back to 1500 for 95%, but 1300 for 94% and 1100 AD for 90%</span>" (<a href="http://amac1.blogspot.com/2010/08/comment-on-mw10-submitted-to.html#more">link</a>).</li>
<li><strike>It's not clear whether the "without" red line excludes suspect hockeystick-shaped tree-ring datasets. Steve McIntyre claims that the red line <a href="http://amac1.blogspot.com/2011/06/tiljander-data-series-appear-again-this.html?showComment=1308885644506#c5257572656773661654">includes bristlecones</a>. </strike> <i>(Update: The red and blue lines both <a href="http://amac1.blogspot.com/2011/06/tiljander-data-series-appear-again-this.html?showComment=1308885644506#c5257572656773661654">include bristlecones</a>, see below.)</i></li>
</ul>A few years ago, Paul Graham posted his memorable essay <a href="http://www.paulgraham.com/say.html">What You Can't Say</a> <i>(link fixed 7/5/11)</i>. I don't want to make him mad, but I'll close this post with a simple question that is still waiting for a clear-cut answer:<br />
<br />
<i>Are the Tiljander proxies calibratable to the instrumental temperature record, 1850-1995?</i><br />
<br />
<i><b>Update, June 25, 2011</b></i><br />
<br />
In the comments, MikeN suggested that I post the graph from Mann09 that shows the portion of the no-dendro/no-Tilj reconstruction that doesn't pass validation. <br />
<br />
That graph is Figure S8 of the S.I. for Mann<i>09</i>. Reference --<br />
<br />
ME Mann, Z Zhang, S Rutherford, RS Bradley, MK Hughes, D Shindell, C Ammann, G Faluvegi, & F Ni, "Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly" (<a href="http://www.meteo.psu.edu/%7Emann/shared/articles/MannetalScience09.pdf">PDF</a>). <a href="http://www.sciencemag.org/content/326/5957/1256.abstract?sid=23ce362c-8836-4ca9-a3e0-ed3c662afa0a">Science 326: 1256-1260 (Nov. 2009)</a> (S.I. at <i>Science</i>).<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiM8hLV-dClN9MWl5nPGrLozTe_nNQenARGewrWtmn-flJ97q1gCCIPT6Mj1z0XfV6rSqVROnPufn6Ti1BgE6v2adboQlBc9cCBofof5TrJmfFm0SGOg1OnV4hOrmO0Tl4dvOXKqA/s1600/Mann09+SI+FigS8-rev0.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="376" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiM8hLV-dClN9MWl5nPGrLozTe_nNQenARGewrWtmn-flJ97q1gCCIPT6Mj1z0XfV6rSqVROnPufn6Ti1BgE6v2adboQlBc9cCBofof5TrJmfFm0SGOg1OnV4hOrmO0Tl4dvOXKqA/s640/Mann09+SI+FigS8-rev0.jpg" width="640" /></a></div>Legend: <br />
<blockquote><span style="color: #660000;"><b>Figure S8: Sensitivity of NH mean reconstruction to exclusion of selected proxy record.</b> Reconstructions are shown based on “all proxy” network (red, with two standard error region shown in yellow) proxy network with all tree-ring records removed (blue), proxy network with a group of 7 long-term proxy with greater uncertainties and/or potential biases as discussed in ref. S1 (brown) and both tree-ring data and the group of 7 records removed (green; dashed before AD 1500 indicates reconstruction no longer passes validation).</span></blockquote>As far as a non-postmodern approach to the question of whether the use of the Tiljander data series "matters": If one is to use this approach, the nearest thing to an apples-to-apples comparison is thus the Blue Line versus the Green Line. (Unfortunately, a two-standard-error region is not shown for either one.) However, it's very hard to see the dashed green line, made worse when it passes beneath the solid blue line. By increasing the magnification of the PDF, most of it can be discerned. In the following figure, I've overwritten the dashed green line in a drawing program, as best I could. The black vertical I added at 1500 AD is a reminder that the green line fails Mann09's validation test at all points prior to that year.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjP14ok8txuIrRrwzLeJtNheBDe328_tO3sEz8ezava_3E44jCf-ttW94kgZWND-HDGWyyCvOhcNXvX6xoMc97bBCLkFoPgmkTs1X9z0R_2ZldPZB5aQxsWI5OEiExpXTWOYPMzxQ/s1600/Mann09+SI+FigS8-rev2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="376" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjP14ok8txuIrRrwzLeJtNheBDe328_tO3sEz8ezava_3E44jCf-ttW94kgZWND-HDGWyyCvOhcNXvX6xoMc97bBCLkFoPgmkTs1X9z0R_2ZldPZB5aQxsWI5OEiExpXTWOYPMzxQ/s640/Mann09+SI+FigS8-rev2.jpg" width="640" /></a></div><blockquote><b>Blue Line</b>: Proxy network, without tree-ring data (no-dendro/yes-Tilj).<br />
<br />
<b>Green Line</b>: Proxy network, without tree-ring data and without 7 proxies with potential problems (no-dendro/no-Tilj).</blockquote>Obviously, this is not the comparison that was offered by Prof. Mann in Update 2 at <i>RealClimate</i>. That graph, reproduced above, showed a Blue Line (with 7 proxies) and a Red Line (without 7 proxies)<strike> from Mann09 S.I. Fig S7b (I believe that was a typo, and that the intent was to refer to Fig. S8.)</strike> <i>(Update 6/25/11: I was in error on this minor point. Prof. Mann didn't specify whether the data in this graph came from Mann<b>08</b> SI Fig. <b>S7b</b> or Mann<b>09</b> SI Fig. <b>S8</b>. It's from the latter.)</i><br />
<br />
<i>RealClimate</i> Update 2 Blue (with 7 proxies) appears to be Mann09 SI Fig. S8 Red (yes-dendro/no-Tilj).<br />
<br />
<i>RealClimate</i> Update 2 Red (without 7 proxies) appears to be Mann09 SI Fig. S8 Brown (yes-dendro/yes-Tilj).<br />
<br />
<i><b>Update, June 26, 2011</b></i><br />
<br />
<strike>Apples to oranges.</strike> <br />
<br />
In discussing Mann09 SI Fig. S8, I quoted Gavin Schmidt on the failure of the Green Line to pass validation at the 95% level prior to 1500 AD. It should be noted that the Blue Line is dashed prior to 700 AD. Presumably, that is where it <i>also</i> failed validation.<br />
<br />
So, <i>if</i> this method of assessing whether Tiljander "matters" is to be used, we have to recognize three parts to a comparison of "yes-Tilj" to "no-Tilj":<br />
<blockquote>* 1850 AD to 1500 AD -- Compare "validated" no-dendro/yes-Tilj to "validated" no-dendro/no-Tilj<br />
<br />
* 1500 AD to 700 AD -- Compare "validated" no-dendro/yes-Tilj to "failed" no-dendro/no-Tilj<br />
<br />
* 700 AD to 500 AD -- Compare "failed" no-dendro/yes-Tilj to "failed" no-dendro/no-Tilj</blockquote>So the apples-to-apples exercise for Mann09 SI Fig. S8 involves evaluating two quite different and sometimes-failed reconstructions. The oranges-to-oranges comparison in <i>RealClimate</i>'s Update 2 is not relevant to whether the use of the Tiljander data series "matters". <br />
<br />
And certainly not relevant to whether these series are calibratable to the instrumental temperature record.<br />
<br />
<u><i>End of June 26, 2011 Update</i></u><br />
<u><i>End of June 25, 2011 Update</i></u><br />
<i>July 6, 2011: I inserted the phrase </i>"Prof. Mann continues:"<i> in the body of the post, for clarity.</i>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com38tag:blogger.com,1999:blog-7805174.post-21160729558463041092011-06-21T13:40:00.000-07:002011-06-25T13:44:57.890-07:00The Tiljander Data Series Appear Again, This Time in a Sea-Level StudyAt <i>RealClimate.org</i>, Stefan Rahmstorf has written "<a href="http://www.realclimate.org/index.php/archives/2011/06/2000-years-of-sea-level/">2000 Years of Sea Level</a>" about a study published on June 20, 2011 in PNAS. Andrew Kemp and co-authors BP Horton, JP Donnelly, ME Mann, M Vermeer, and S Rahmstorf reconstruct sea levels from 500 AD to the present, and relate these levels to the temperatures of the past, using a multi-proxy reconstruction that was first presented in Mann et al. (PNAS, 2008). (The Kemp11 PDF can be downloaded at the RC post.)<br />
<br />
It turns out that the chosen temperature recon is heavily dependent on the <strike>four</strike> <i>three</i> uncalibratable Tiljander data series. This reliance grows stronger as one goes back in time, and shorter (younger) records "drop out."<br />
<br />
I tried to leave a remark on this subject at <i>RealClimate.org</i>. Apparently, that site is set to automatically fail any comment tagged with my user name, email, or IP address. Here is the local copy of what I submitted (21 Jun 3:50 PM EDT) --<br />
<blockquote>I was surprised at the provenance of the paleotemperature reconstruction that was used in Kemp et al's Fig. 2A and Fig. 4A. According to Fig. 2A's legend, it is "Composite EIV global land plus ocean global temperature reconstruction, smoothed with a 30-year LOESS low-pass filter". The reference is Mann et al. (2008). In that paper's S.I., the unsmoothed version is in panel F of Fig S6, as the black line labelled "Composite (with uncertainties)".<br />
<br />
This is one of the multiproxy reconstructions that employed the four (actually three) uncalibratable Tiljander lakebed sediment data series.<br />
<br />
According to Gavin Schmidt, "...it's worth pointing out that validation for the no-dendro/no-Tilj is quite sensitive to the required significance, for EIV NH Land+Ocean it goes back to 1500 for 95%, but 1300 for 94% and 1100 AD for 90%" (<a href="http://amac1.blogspot.com/2010/08/comment-on-mw10-submitted-to.html#more">link</a>). Further remarks on this issue as Responses to other RC comments <a href="http://www.realclimate.org/?comments_popup=4431#comment-183182">here</a> (see numbers 525, 529, and 531).<br />
<br />
The incorrect inclusion of Tiljander could well make this EIV reconstruction progressively worse, as one goes from 1500 AD back to 500 AD. This might explain the increasing divergence between the temperature recon and the sea-level recon, as one travels back from 1100 AD to the beginning of the recons at 500 AD. This pattern is shown in Kemp11's S.I. Figs. S3, S4, and S5.<br />
<br />
Did any of the peer reviewers comment on this issue, or request that you use a no-Tiljander temperature reconstruction?</blockquote><a name='more'></a>I left a more detailed version at <i>Collide-a-scape</i> as #128 at <a href="http://www.collide-a-scape.com/2011/06/17/climate-critics-that-wont-muzzle-themselves/comment-page-3/#comment-65784">Climate Critics That Won't Muzzle Themselves</a> (June 21st, 2011 at 1:35 pm; lightly edited) --<br />
<blockquote>...Yesterday, Kemp et al. 2011 was published in PNAS, relating sea-level variation to climate over the past 1,500 years (<a href="http://www.upenn.edu/pennnews/news/penn-researchers-link-fastest-sea-level-rise-two-millennia-increasing-temperatures">UPenn press release</a>). Among the authors is Prof. Mann. Figs. 2A and 4A are "Composite EIV global land plus ocean global temperature reconstruction, smoothed with a 30-year LOESS low-pass filter". This is one of the multiproxy reconstructions in Mann et al. (2008, PNAS). The unsmoothed tracing appears as the black line labelled "Composite (with uncertainties)" in panel F of Fig. S6 of the "Supporting Information" supplement to Mann08 (downloadable from <a href="http://www.pnas.org/content/105/36/13252.abstract?sid=17be9c27-0253-496f-851c-e67de7d40fbd">pnas.org</a>).<br />
<br />
This is one of the Mann08 reconstructions that made use of the four (actually three) uncalibratable Tiljander data series.<br />
<br />
As scientist/blogger Gavin Schmidt has indicated, the early years of the EIV Global reconstruction rely heavily on Tiljander to pass its "validation" test: "...it's worth pointing out that validation for the no-dendro/no-Tilj is quite sensitive to the required significance, for EIV NH Land+Ocean it goes back to 1500 for 95%, but 1300 for 94% and 1100 AD for 90%" (<a href="http://amac1.blogspot.com/2010/08/comment-on-mw10-submitted-to.html#more">link</a>). Also see RealClimate <a href="http://www.realclimate.org/?comments_popup=4431#comment-183182">here</a> (Gavin's responses to comments 525, 529, and 531).<br />
<br />
The dependence of the first two-thirds of the EIV recon on the inclusion of Tiljander's data series isn't mentioned in the text of Kemp11. Nor is it discussed in the SI (<a href="http://www.pnas.org/content/early/2011/06/13/1015619108.abstract">link</a>), although it is an obvious and trivial explanation for the pre-1100 divergence noted in the SI's Figures S3, S4, and S5.<br />
<br />
Peer review appears to have been missing in action on this glaring shortcoming in Kemp11's methodology.<br />
<br />
More than anything, I am surprised by this zombie-like re-appearance of the Tiljander data series -- nearly three years after the eruption of the controversy over their misuse as temperature proxies!</blockquote>Interestingly, M. Vermeer discussed the Tiljander <strike>proxies</strike> <i>data series</i> with me and others in the comments of Arthur Smith's posts <a href="http://arthur.shumwaysmith.com/life/content/wheres_the_fraud">Where's the fraud?</a> and <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors">Michael Mann's errors</a>. So at least one of Kemp11's authors was familiar with the (claimed) severe shortcomings of Tiljander-based reconstructions. And then... they went ahead and used just that type of recon.AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com24tag:blogger.com,1999:blog-7805174.post-79473073024441379112010-08-22T05:53:00.000-07:002010-08-23T04:54:46.163-07:00A comment on M+W10 submitted to RealClimate.org<span style="font-size: 85%;">I submitted a comment to the <i>RealClimate.org</i> post <a href="http://www.realclimate.org/index.php/archives/2010/08/doing-it-yourselves/">Doing it yourselves</a> (20 August 2010), as the author makes some interesting remarks on the intersection of McShayne and Wyner (2010) and the Tiljander proxies. My comment entered the moderation queue last night after position #41, and wasn't among the ten comments that have been released in three batches this morning. Perhaps it has been failed, or perhaps it's being delayed. If does make a belated appearance (accompanied with inline commentary?), I'll note that in an update.<br />
<br />
[ UPDATE 22 Aug. 2010 3:20 PM EDT -- In the past hour, my comment passed moderation, and was slotted into <a href="http://www.realclimate.org/index.php/archives/2010/08/doing-it-yourselves/comment-page-1/#comment-184902">position #42</a> (the comment count is currently at 60). Gavin Schmidt's inline commentary is reproduced at the tail of this post. -- AMac ]<br />
</span><br />
<a name='more'></a><br />
<span style="font-size: 85%;"><br />
"M&W10" is the recently-released preprint of "A Statistical Analysis of Multiple Temperature Proxies: Are Reconstructions of Surface Temperatures Over the Last 1000 Years Reliable?," by BB McShane and AJ Wyner. Because it questions the methodology of Mann08, it's already beloved by many critics of the AGW Consensus. However, this is a very lengthy and complex statistical treatment that is performed by two non-paleoclimatologists, done without the benefit of insights from insiders. It has, predictably, been slammed by the most-capable pro-AGW Consensus science-bloggers. It seems to me that many of these critiques have merit: the authors would benefit from a rewrite (and a shortening/focusing), if this is possible at this late stage in the submission process. <br />
<br />
That said, what I take as M&W10's major point seems very timely: a focus on the tightness of the <i>uncertainty estimates</i> that accompany paleoclimate reconstructions like those published by Prof. Mann's group (M&W10 takes Mann08 as its jumping-off point). My sense is that the confidence expressed by the narrowness of these papers' uncertainty bars is very misplaced. Of course these are opinions. I don't claim the statistical chops to comment in detail on M&W10's methods.<br />
<br />
The figure in "Doing it yourselves" that touches on the Lake Korttajarvi data series is reproduced (fair use) below. Here is the paragraph that accompanies it --<br />
<blockquote>It’s also easy to test a few sensitivities. People seem inordinately fond of obsessing over the Tiljander proxies (a set of four lake sediment records from Finland that have indications of non-climatic disturbances in recent centuries – two of which are used in M&W). So what happens if you leave them out?</blockquote><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_VIMjdy8f8UE_cKxTPolVKe3X7_92yzx-MGiVEjkXgBv8TL1I_6P9jWhqCmmNTzj9OVDAHL6fhkosHOVrmecwmFe_7OLU3xBThhnFJd2c8Mhj6RZnDnUHSJ0VBVgq760M-o1-Pg/s1600/RC-DIY-fig14_notilj.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="250" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_VIMjdy8f8UE_cKxTPolVKe3X7_92yzx-MGiVEjkXgBv8TL1I_6P9jWhqCmmNTzj9OVDAHL6fhkosHOVrmecwmFe_7OLU3xBThhnFJd2c8Mhj6RZnDnUHSJ0VBVgq760M-o1-Pg/s400/RC-DIY-fig14_notilj.jpg" width="400" /></a></div><br />
That figure seemed bereft of context. It is referring to which of M&W10's sections? Using M&W10's methods, the <i>Realclimate</i> authors are excluding the Tiljander proxies from... <i>what</i>, exactly?<br />
<br />
So I submitted the following comment. Rereading it, I see that I edited away my "a question" during one of my rewrites. That is, "Could you show the output of your M&W10-style 'Lasso' reconstructions for Non-Dendro proxies and for Non-Dendro/Non-Tiljander proxies? Those would be comparable to the Non-Dendro and Non-Dendro/Non-Tiljander traces in the current version of Mann08's Fig S8a."<br />
<br />
<a href="http://amac1.blogspot.com/">AMac</a> says:<br />
<i>Your comment is awaiting moderation.</i><br />
<a href="http://www.realclimate.org/index.php/archives/2010/08/doing-it-yourselves/comment-page-1/#comment-184902">21 August 2010 at 9:59 PM</a><br />
<blockquote>A question, and two points of clarification.<br />
<br />
First, thanks for the graphics that show various "Lasso" outputs with the Tiljander proxies omitted. This post's "No Tiljander Proxies" figure with the six reconstructions (1000 AD - 2000 AD) is an extension of M&W10's Figure 14. As such, it's a little hard to interpret without reference to that legend.<br />
<br />
According to Fig. 14:<br />
<br />
* The dashed Green line is the M&W10 backcast for Northern Hemisphere land temperature that employs the first 10 principal components on a global basis.<br />
<br />
* The dashed Blue line is the backcast for NH land temperature that employs the first 5 PCs (global), as well as the first 5 local (5x5 grid) PCs.<br />
<br />
* The dashed Red line is the backcast for NH land temperatures that employs only the first PC (global).<br />
<br />
All three dashed lines appear to be based on the use of the entire data set used in Mann et al, (PNAS, 2008)--<i>both Tree-Ring proxies and Non-Dendro proxies.</i><br />
<br />
This is an important consideration, as there seems to be general agreement that Mann08's <b>Dendro-Including</b> reconstructions are not grossly affected by the exclusion of the Tiljander proxies. This point was made in Mann08's Fig. S8a (all versions).<br />
<br />
However, there has been much contention over the extent to which NH land reconstructions <i>restricted to non-dendro proxies</i> are affected by the inclusion or exclusion of the Tiljander varve data. See, for example, the 6/16/10 <i>Collide-a-scape</i> thread <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/">The Main Hindrance to Dialogue (and Detente)</a>.<br />
<br />
Mann08 achieved prominence because of its novel findings: the claim of consistency among reconstructions based on Dendro proxies, and those based on Non-Dendro proxies. Mann08 also claimed that the use of Non-Dendro proxies in could extend validated reconstructions far back in time. This is stated in Mann08's <a href="http://www.pnas.org/content/early/2008/09/02/0805721105">abstract</a> (see also <a href="http://live.psu.edu/story/34169">press release</a>).<br />
<br />
Thus, the matters of interest would be addressed if the dashed and solid traces in this post's "No Tiljander Proxies" figure were based only on the relevant data set: the <i>Non-Dendro</i> proxies. <br />
<br />
(The failure of Non-Dendro reconstructions to validate in early years in the absence of Tiljander was raised by Gavin in <a href="http://www.realclimate.org/?comments_popup=4431#comment-182703">Comment #414</a> of "The Montford Delusion" thread (also see #s 483, 525, 529, and 531). While progress in that area would be welcome, it is probably difficult to accomplish with M&W10's Lasso method.)<br />
<br />
.<br />
The first point of clarification is that the Tiljander proxies cannot be meaningfully calibrated to the instrumental temperature record, due to increasing influence of non-climate factors post-1720 (<a href="http://amac1.blogspot.com/2010/08/synopsis-of-some-tiljander-related.html">Discussion</a>). This makes them unsuitable for use by the methods of Mann08 -- and thus by the methods of M&W10 -- which require the calibration of each proxy to the 1850-1995 temperature record.<br />
<br />
.<br />
The second point of clarification is concerns this phrasing in the post:<br />
<blockquote>People seem inordinately fond of obsessing over the Tiljander proxies (a set of four lake sediment records from Finland that have indications of non-climatic disturbances in recent centuries – two of which are used in M&W).</blockquote>The "four lake sediment records" used in Mann08 are "Darksum," "Lightsum," "XRD," and "Thickness." The authors of Tiljander et al (Boreas, 2003) did not ascribe meaning to "Thickness," because they derived "Darksum" by subtracting "Lightsum" from "Thickness." Thus, "Thickness" contains no information that is not already included in "Lightsum" and "Darksum."<br />
<br />
In other words, there are effectively only <i>three</i> Tiljander proxies (<a href="http://amac1.blogspot.com/2010/08/tiljander-data-series-data-and-graphs.html">Figure</a>). </blockquote>- - - - - - - - - -<br />
<br />
M&W10's Figure 14 is reproduced (fair use) below:<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbkHELhXZqdf-f5vEvOD2rMjhHyycpp6S-92RXAdQ7x8-4ETBmC4QF5yXzoYwRtI0DBGUUYyDijIU4Qc8ed_iSlb1OHAeOu_QksKbDe2SH1M4CTIIk3YcHRDBWsP8UAcywIqiRRw/s1600/MW10-Fig14.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="222" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbkHELhXZqdf-f5vEvOD2rMjhHyycpp6S-92RXAdQ7x8-4ETBmC4QF5yXzoYwRtI0DBGUUYyDijIU4Qc8ed_iSlb1OHAeOu_QksKbDe2SH1M4CTIIk3YcHRDBWsP8UAcywIqiRRw/s400/MW10-Fig14.png" width="400" /></a></div><blockquote><blockquote><i>FIG 14. Backcasts to 1000 AD from the various models considered in this section are plotted in grey. CRU Northern Hemisphere annual mean land temperature is given by the thin black line with a smoothed version given by the thick black line. Three forecasts are featured: regression on one proxy principal component (red), regression on ten proxy principal components (green), and the two stage model featuring five local temperature principal components and five proxy principal components (blue).</i></blockquote></blockquote>- - - - - - - - - -<br />
<br />
[ UPDATE 22 Aug. 2010 3:20 PM -- My comment passed moderation and was slotted into position #42, with its original timestamp of 21 August 2010 at 9:59 PM. Gavin Schmidt's inline commentary follows, with <i>[Notes]</i> for my follow-ups inserted. -- AMac ]<br />
<br />
<blockquote>[<b>Response:</b> We aren't going to go over your issues with Mann et al (2008) yet again <i>[Note 1]</i> - though it's worth pointing out that validation for the no-dendro/no-Tilj is quite sensitive to the required significance, for EIV NH Land+Ocean it goes back to 1500 for 95%, but 1300 for 94% and 1100 AD for 90% (<a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxySpatial09/">see here</a>). But you missed the point of the post above entirely. The point is not that M&W have the best method and it's sensitivities need to be examined, but rather that it is very easy to edit the code and do what ever you like to understand their results better i.e. "doing it yourself".<i>[Note 2]</i> If you want a no-dendro/no-Tiljander reconstruction using their methodology, then go ahead and make it (it will take just a few minutes - I know, I timed it - but to help you along, you need to change the selection criteria in R_fig14 to be <code>sel < - (allproxy1209info[,"StartYear"] <= 1000) & (allproxy1209info[,2] != 7500) & (allproxy1209info[,2] != 9000)</code> (no_dendro) and change the line <code>proxy < - proxy[,-c(87:88)]</code> to <code>proxy < - proxy[,-c(32:35)]</code> (no_tilj)). <i>[Note 3]</i> Note that R_fig14 does not give any info about validation, so you are on your own there. The bottom line is that it still <a href="http://www.realclimate.org/images/fig14_nodendronotilj.jpg">doesn't make much difference</a> (except the 1PC OLS case, which doesn't seem very sensible either in concept or results anyway). <i>[Note 4]</i> - gavin]</blockquote><br />
<i>[Note 1]</i> There is no "yet again" to discuss. The problems with Tiljander have never been addressed. Not by Dr. Schmidt, not by Prof. Mann, not by any of Mann08's other authors. As stated in my comment, the main issue is that the Tiljander proxies cannot be calibrated to the instrumental record, and thus are wholly unsuited to Mann08's methods.<br />
<br />
<i>[Note 2]</i> It is silly to propose that I have "missed the point of the post entirely." It is silly to suggest that I've claimed that M&W10 "have the best method and it's sensitivities need to be examined."<br />
<br />
<i>[Note 3]</i> Like most pro-AGW-Consensus advocates, most lukewarmers, and most skeptics: I am not conversant in either "R" or MatLab. Thus, I cannot immediately profit from Dr. Schmidt's sincere and well-meaning advice.<br />
<br />
<i>[Note 4]</i> Dr. Schmidt links to the No-Dendro/No-Tiljander variant of M&W10's Figure 14 that he generated: <br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-WjrhO0RtlcGaXkCIO-j2pQa3n9Prfc31URnX9YY5-7e-Iin0I1KfTKNB_b-7FwK9dv-iUyogoyb8YvD5WbGivNNglxw-EcAnast60cV_gu5LHuXaEhRVKKwFBQs3Un1SMX3jpA/s1600/RC-DIY-Fig14_nodendronotilj.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="250" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-WjrhO0RtlcGaXkCIO-j2pQa3n9Prfc31URnX9YY5-7e-Iin0I1KfTKNB_b-7FwK9dv-iUyogoyb8YvD5WbGivNNglxw-EcAnast60cV_gu5LHuXaEhRVKKwFBQs3Un1SMX3jpA/s400/RC-DIY-Fig14_nodendronotilj.jpg" width="400" /></a></div><br />
<i>That</i> is an informative figure! It suggests that exclusion of the Tiljander proxies does not greatly alter the Non-Dendro reconstructions obtained by M&W10's "Lasso" method, if the first 10 global PCs are used (Green), or if the first 5 global PCs and the first 5 gridded PCs are used (Blue). On the other hand, the use of only the first global PC shows something interesting. Adding in the uncalibratable Tiljander proxies completely changes the character of the first principal component. Without it, PC1 of the Non-Dendro proxies <strike>follows</strike> <i>causes the anomaly trace (solid Red line) to follow</i> the approximate general path <strike>of the</strike> <i>followed by the anomaly trace when governed by the</i> 10 global PCs and the 5 global PCs plus 5 gridded PCs <strike>(solid Red line)</strike>. Add in Tiljander (dashed Red line), and <i>the</i> PC1<i>-governed trace</i> flatlines around -0.3 C for the duration of the reconstruction. <br />
<br />
Perhaps those better-versed than me in principal component analysis will be able to make more sense of this figure.<br />
<br />
[ UPDATE 23 Aug. 2010 -- Wording two paragraphs up altered. In reviewing Gavin's new No-Dendro/No-Tilj reconstruction figure, I am discussing the shapes of the anomaly traces governed by the principal component(s). These are not the PCs themselves -- AMac ]<br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com10tag:blogger.com,1999:blog-7805174.post-17172673458234724762010-08-16T22:54:00.000-07:002011-08-14T12:49:36.336-07:00The Tiljander Data Series: Data and Graphs<span style="font-size: 85%;">I have compiled the information from the Lake Korttajarvi <strike>borehole</strike> <i>varved sediments record</i> that was characterized in Tiljander03, and then used in the multiproxy paleoclimate reconstruction Mann08. <br />
<br />
The Excel file containing this data can be downloaded from <a href="https://bitbucket.org/amac/tiljander-proxy-graphs/downloads">this BitBucket.org archive</a>. <strike>The name of the 1.5MB file is Tiljander-Mann08-proxies-data+graphs.xls.</strike> The name of the 1.8 MB file is <a href="https://bitbucket.org/amac/tiljander-proxy-graphs/downloads/Tiljander_proxies_dataset_graphs.xls">Tiljander_proxies_dataset_graphs.xls </a>.<br />
<br />
Some observations and some graphs follow.<br />
</span><br />
<a name='more'></a><span style="font-size: 85%;"><b>Observations</b><br />
<br />
The data sets accumulated by Mia Tiljander and coworkers were deposited at NOAA by Prof. Mann's group, along with all of the other proxies they used in Mann08. Once unzipped, the files can be seen to be in two sets of four text files. The four are the Darksum, Lightsum, Thickness, and X-Ray Density data series. The two are the "Original" and the "Infilled" versions. Tiljander's data apparently ends in 1985. To extend it to the end of the screening period used in Mann08 (1850-1995), the final 9 years were "infilled" -- actually, extrapolated, by RegEM (I believe). This nine year period accounts for 6% of the full screening period; obviously a somewhat greater proportion when it is split into calibration and validation sub-periods.<br />
<br />
<br />
Mann08's authors transformed all four of the data series by taking their natural logarithms. Presumably this is how they were screened and calibrated. <br />
<br />
<strike>Typically, data is log-transformed for one of a few reasons:<br />
<br />
* There is an a priori physical reason to expect an exponential relationship between the data set, and other variables.<br />
<br />
* The data has a log-normal (or near-log-normal) distribution, rather than a normal (Gaussian) one.<br />
<br />
* It is more convenient to use log-transformed data.<br />
<br />
I know of no evidence that either of the first two conditions holds.</strike> [Update 18 Aug 2010: I struck the previous few sentences: log transformation of varve data seems to be an accepted practice in paleolimnology. See the Update at the end of the post -- AMac]<br />
<br />
<br />
Darksum, Lightsum, and Thickness are all measurements of varve thickness in millimeters, though Darksum and Lightsum are expressed as tenths of microns (i.e. as a 10,000x larger number). Darksum is derived from a very simple relationship:<br />
<br />
Darksum = Thickness - Lightsum<br />
<br />
[Illustration added 8/17/10; click to embiggen]<br />
</span><br />
<div class="separator" style="clear: both; text-align: center;"><span style="font-size: 85%;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQF1WOMUlB7o_1MEPHCQAK9dETo7TN3Rq-a_DYCVsReztUb4SUXHXz1-FcZ5LpYNcV77EzpQn32cHm4d9JM1fSmipHh0bpYdtWRBZ5vGn1SF7-2UPOBrRJCgfrEulpW4P-5NjfFQ/s1600/LS+DS.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQF1WOMUlB7o_1MEPHCQAK9dETo7TN3Rq-a_DYCVsReztUb4SUXHXz1-FcZ5LpYNcV77EzpQn32cHm4d9JM1fSmipHh0bpYdtWRBZ5vGn1SF7-2UPOBrRJCgfrEulpW4P-5NjfFQ/s400/LS+DS.png" width="400" /></a></span></div><span style="font-size: 85%;"><br />
From this, it is obvious that there are at most two degrees of freedom among the three data sets. Mann08's authors were arguably in error to use all of them in their reconstructions.</span><br />
<span style="font-size: 85%;"><br />
<br />
<b>Charts</b><br />
<br />
What follows are a series of traces generated by Excel, one for each of the four Tiljander proxies, with limited commentary. The following should be kept in mind:<br />
<br />
According to Tiljander03's claims:<br />
<br />
Prior to about 1720, climate signals are present in these three data series: Darksum, Lightsum, and X-Ray Density. Tiljander03 doesn't interpret Thickness.<br />
<br />
For Darksum, <i>higher</i> values correspond to <i>warmer</i> and wetter summers with longer growing seasons.<br />
<br />
For Lightsum, <i>higher</i> values correspond to <i>cooler</i> and wetter winters with more pronounced spring snowmelt.<br />
<br />
For <strike>Darksum,</strike> <i>XRD,</i> <i>higher</i> values correspond to <i>cooler</i> periods, reflecting a mix of Darksum and Lightsum.<br />
<br />
<br />
For the pictures that follow, I haven't adhered to Tiljander03's interpretation--it is simpler to graph everything such that larger values are up, whatever the climactic meaning of rising signals may be. For further perspective, see the discussion between scientist/TCO and me, at <a href="http://amac1.blogspot.com/2010/08/synopsis-of-some-tiljander-related.html">this post</a> (warning, it is a long, two-part exchange).</span><br />
<br />
<span style="font-size: 85%;">After about 1720, the Lake Korttajarvi sediments became progressively more contaminated as a result of local human activities. These included farming, roadbuilding, peat cutting, eutrophication, and bridge reconstruction. <br />
<br />
Also (not in Tiljander03), the Geological Survey of Finland noted that the water level of the lake was altered by farmers, sometime after 1700. The account is in Finnish, and lacks detail.<br />
<br />
<br />
First, here are the four proxies, from 200 AD to the near-present (Mann08's infilled values 1986-1995 are used). The red and green traces are the annual varve data, while the centered black line is the same data, smoothed with an 11-year rolling average (my choice of filter). The scale for the Thickness, Darksum, and Lightsum have been kept comparable -- in these three cases, "millimeters of varve thickness" is being graphed. (You may have to scroll to the left or increase the size of your browser window to get a complete view of these first two graphs.)<br />
</span><br />
<span style="font-size: 85%;"></span><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgl1RECPYS-Q-L-giqAbkVIBsxao3JJw3A_hUuxsw09viBHJU9c9VB-Y8UTPrr08_T92O12vMn_vWkGeOOSjvWBeXpeE4xCA23t2IwAMgwJtpVCIpS5xHz7ui4YYOhkURslhDqElA/s1600/Thickness+Darksum.png" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="280" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgl1RECPYS-Q-L-giqAbkVIBsxao3JJw3A_hUuxsw09viBHJU9c9VB-Y8UTPrr08_T92O12vMn_vWkGeOOSjvWBeXpeE4xCA23t2IwAMgwJtpVCIpS5xHz7ui4YYOhkURslhDqElA/s640/Thickness+Darksum.png" width="640" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGB_licId9GGKW6q_plmzMZrlWIVGD4rKDFBWjdBU4eZW8jVaNrpu9qOyujzIxb3_mJE1SoXcexLGQh5bc2Ea53u2-1pI7rBb3PkG-1ALT48FfJy7Yuz9VD4-DUqxoFBhLunUOcA/s1600/Lightsum+XRD.png" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="280" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjGB_licId9GGKW6q_plmzMZrlWIVGD4rKDFBWjdBU4eZW8jVaNrpu9qOyujzIxb3_mJE1SoXcexLGQh5bc2Ea53u2-1pI7rBb3PkG-1ALT48FfJy7Yuz9VD4-DUqxoFBhLunUOcA/s640/Lightsum+XRD.png" width="640" /></a></div><span style="font-size: 85%;"><br />
In the second set of charts, I have simply calculated the mean and standard deviation of the data series (millimeters of varve thickness; arbitrary units for XRD) by century from the 3rd Century on, as a measure of variability. "Standard deviation" has limits in this setting, as these time series are likely autocorrelated to some extent--but it is an acceptable first shot, I think.<br />
<br />
Notice the pattern that holds through the 18th Century, before changing in the 19th and then quite drastically in the 20th (through 1995, including the infilled values).</span><br />
<span style="font-size: 85%;"><br />
</span><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaFak0Gvjjg3QY8nqt6HcUn-H1vVTidqI65WK_RM6ea9HMjfa70VFg9FozJYG7h535TKkphnUCtUs_ly55NKrXXB1adLK8mb_unBqfXpkiy5WRT9OQ3gGm1uWvK2vttNBWu13fhg/s1600/Darksum-SD.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="230" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaFak0Gvjjg3QY8nqt6HcUn-H1vVTidqI65WK_RM6ea9HMjfa70VFg9FozJYG7h535TKkphnUCtUs_ly55NKrXXB1adLK8mb_unBqfXpkiy5WRT9OQ3gGm1uWvK2vttNBWu13fhg/s400/Darksum-SD.png" width="400" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkk0b3LTLcoeh2np_cBPhPXvsqad2JRgt4k8Q_0mdpy2ZZXjIHsoxVChzXdT_Y_PTgroS0OvIRfGSwFtP0YX37IyClHa_N0HDFF1BVLNmkKcuu-ju_HytkUJ1rQzeKKKB6Di3oSQ/s1600/Lightsum-SD.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkk0b3LTLcoeh2np_cBPhPXvsqad2JRgt4k8Q_0mdpy2ZZXjIHsoxVChzXdT_Y_PTgroS0OvIRfGSwFtP0YX37IyClHa_N0HDFF1BVLNmkKcuu-ju_HytkUJ1rQzeKKKB6Di3oSQ/s400/Lightsum-SD.png" width="400" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1wCXIjv65m8ZnNuD5RJr2X5d8KY5MhsoPZaOfxKbD0RkIfyEWaH3IIzWtkTLvgfbYyai7RDUVPIaTGEYhvyk3EeW-NLoJqC-D-dNDsNzJhtkVOUE5MqWnwcasMautb8sFlyQYCw/s1600/Thickness-SD.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="223" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1wCXIjv65m8ZnNuD5RJr2X5d8KY5MhsoPZaOfxKbD0RkIfyEWaH3IIzWtkTLvgfbYyai7RDUVPIaTGEYhvyk3EeW-NLoJqC-D-dNDsNzJhtkVOUE5MqWnwcasMautb8sFlyQYCw/s400/Thickness-SD.png" width="400" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilU6QXGKk2iKh7-GB3PErXhBZMgffmIKRSyH98dT1yeUWEy8AACABW1nWppnVGtxrFlpV_B0bRY2Ne73j2sn4lZspwR55SsaZYeQBHtGzkR7slhNQEbD7VFKdIGmBXjxDjUS_ukQ/s1600/XRD-SD.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="222" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilU6QXGKk2iKh7-GB3PErXhBZMgffmIKRSyH98dT1yeUWEy8AACABW1nWppnVGtxrFlpV_B0bRY2Ne73j2sn4lZspwR55SsaZYeQBHtGzkR7slhNQEbD7VFKdIGmBXjxDjUS_ukQ/s400/XRD-SD.png" width="400" /></a></div><br />
<span style="font-size: 85%;">In all four cases, the 18th Century appears to have characteristics that resemble earlier periods more than the 19th and 20th Centuries. Thus, to get a sense of what a "normal" century looks like next to the "unusual" period that includes the 1850-1995 interval, I graphed each data series from 1700 through 1995, along with the synthetic temperature-anomaly reconstruction that Mann08's authors used for CPS. This is the 5-degree by 5-degree gridcell for Southern Finland that includes Lake Korttajavi. Details at <a href="http://amac1.blogspot.com/2010/06/ari-jokimaki-looks-at-tiljander-proxies.html">this post</a>. (There is a local weather station with records dating back to the 1890s whose data are depicted in Tiljander03. That is probably a better representation of local climate; it appears to trend more-or-less stably over the 20th Century, with less upward trend than the gridcell shows. I haven't located that information, though.) Note that raw data (millimeters of varve thickness, or arbitrary grayscale units (XRD)) are used here, rather than the log-transformed variants.</span><br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBKOxXRD9nMtpO7zX4SZ9y_k-jR8r7SgmWoq4AiEEV98hAIL_L1m-H4PJmUpWviK_a-krr1sMy9eUcWrkdjTzV_JrGZSJGBN2SIS7IOzUSMFgaXDTHSI4WugtyTl8T9x-u6-1arQ/s1600/Daarksum-1700.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="340" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBKOxXRD9nMtpO7zX4SZ9y_k-jR8r7SgmWoq4AiEEV98hAIL_L1m-H4PJmUpWviK_a-krr1sMy9eUcWrkdjTzV_JrGZSJGBN2SIS7IOzUSMFgaXDTHSI4WugtyTl8T9x-u6-1arQ/s400/Daarksum-1700.png" width="400" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2crCx2NoRwI8ugXA1lqv6yrP-uRl_CcJfoGy0yB7bh8zoT72J9oWBHfQ_osjIHpezW-CkeTVQtPkVWM-5txdmT5BDLpVuNFs89bBYtKtYiqWzI0_AIoemgHxqy4W94hzAeB1wPQ/s1600/Lightsum-1700.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="338" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2crCx2NoRwI8ugXA1lqv6yrP-uRl_CcJfoGy0yB7bh8zoT72J9oWBHfQ_osjIHpezW-CkeTVQtPkVWM-5txdmT5BDLpVuNFs89bBYtKtYiqWzI0_AIoemgHxqy4W94hzAeB1wPQ/s400/Lightsum-1700.png" width="400" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhckYkDr5hI0R2wWFHfPes2RjtWKPGkl-ew1BqirHtG7ND5VLZ5_k4ktE4EZ0z4Ss_QVJnlO1yZkx38_NdFxeAN1Clswq5-d-dq-AN-fj2fKFDzNGTgsO9taZ7N9mhHI1JjULI9iQ/s1600/Thickness-1700.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="337" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhckYkDr5hI0R2wWFHfPes2RjtWKPGkl-ew1BqirHtG7ND5VLZ5_k4ktE4EZ0z4Ss_QVJnlO1yZkx38_NdFxeAN1Clswq5-d-dq-AN-fj2fKFDzNGTgsO9taZ7N9mhHI1JjULI9iQ/s400/Thickness-1700.png" width="400" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiILh8g8d4BdXS_GIJRya7TNGvwITdFac_L_cqoxdL-4rcM5zmNNyGzxnFcgAayY8nOLa8PchsEUcjrBwEcfjP6_aARPhJtdunIC4LhnevrFffeWOIJFdrcRYuxgsSZ3vau_kRyUw/s1600/XRD-1700.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="338" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiILh8g8d4BdXS_GIJRya7TNGvwITdFac_L_cqoxdL-4rcM5zmNNyGzxnFcgAayY8nOLa8PchsEUcjrBwEcfjP6_aARPhJtdunIC4LhnevrFffeWOIJFdrcRYuxgsSZ3vau_kRyUw/s400/XRD-1700.png" width="400" /></a></div><br />
<span style="font-size: 85%;">Finally, here are graphs showing my attempt to show the correlation between proxy and temperature over the entire 1850-1995 period. For this series, unsmoothed log-transformed data is used--although an 11-year trailing rolling average provides a modest boost in R^2 (charts of "ln(proxy)(11-yr-avg) vs time" and of correlations with 11-year smoothed log-transformed data are provided in the Excel file at BitBucket.org). A caveat: note that Mann08 uses the metric "r", while Excel -- and thus I -- have used "R^2".</span><br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvUhN47cUpWChSb3ShYo6QIOrZf2L__IKqx16jVDy8q10kiPUNQrNhB8F3fzEKZZI52bLhiL3CIS7pM07GoYQCWyfwAthShoAxASDxQumZMBBjoNe0pQSJqrHGwsH7hd8Wzef2lA/s1600/Darksum-v-anomaly.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="395" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvUhN47cUpWChSb3ShYo6QIOrZf2L__IKqx16jVDy8q10kiPUNQrNhB8F3fzEKZZI52bLhiL3CIS7pM07GoYQCWyfwAthShoAxASDxQumZMBBjoNe0pQSJqrHGwsH7hd8Wzef2lA/s640/Darksum-v-anomaly.png" width="640" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNAvipHJXc6a8bQ5jpe4nGQwURK1SioZp3oHLmHwlFI4BVjSiwC7vsyV8d1RL-WkhQtk2k7v0tgW4Pa-Jw5osyENrYZ8DFalIszEFW9wVzcI11QyIjuGb_kgYV4RbQUycDmtm9Zw/s1600/Lightsum-v-anomaly.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="395" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNAvipHJXc6a8bQ5jpe4nGQwURK1SioZp3oHLmHwlFI4BVjSiwC7vsyV8d1RL-WkhQtk2k7v0tgW4Pa-Jw5osyENrYZ8DFalIszEFW9wVzcI11QyIjuGb_kgYV4RbQUycDmtm9Zw/s640/Lightsum-v-anomaly.png" width="640" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkjbNWuF-oRUhSxFU1-69A4EulIZvY_UF5M4rTZzSGlPEx3H6nbQdXUNUuUFii7EubeL7Uy_ZBNsRKTvXo1gK4Et2vgAZoeg0M0OMNiczwupRdzpviFyN-ilGI60oimwalS4FGMw/s1600/Thickness-v-anomaly.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="395" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkjbNWuF-oRUhSxFU1-69A4EulIZvY_UF5M4rTZzSGlPEx3H6nbQdXUNUuUFii7EubeL7Uy_ZBNsRKTvXo1gK4Et2vgAZoeg0M0OMNiczwupRdzpviFyN-ilGI60oimwalS4FGMw/s640/Thickness-v-anomaly.png" width="640" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgvyUkz532RzevVNPerh2rjP9PAnmDsL5KvA43pM4od4u70afQKU-qBVsSD-0tEfZtGh96BUrqKcvlcXqjwl5hSpQU8qSUJwjgPljJhJHRnPTo7nRsPbCHmxshuxaR0OCg1GY1iYw/s1600/XRD-v-anomaly.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="395" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgvyUkz532RzevVNPerh2rjP9PAnmDsL5KvA43pM4od4u70afQKU-qBVsSD-0tEfZtGh96BUrqKcvlcXqjwl5hSpQU8qSUJwjgPljJhJHRnPTo7nRsPbCHmxshuxaR0OCg1GY1iYw/s640/XRD-v-anomaly.png" width="640" /></a></div><br />
<span style="font-size: 85%;">As promised: lots of data, with little editorializing!<br />
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[<b>UPDATE</b> 18 Aug 2010 -- Two good comments on the subject of logarithmic transformation of varve data were left at the Air Vent's post <a href="http://noconsensus.wordpress.com/2010/08/18/mw10-some-thoughts/#comment-34674">MW10 -- Some thoughts</a>. Reproduced below. -- AMac]<br />
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#4 -- BobN -- August 18, 2010 at 11:31 am<br />
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<blockquote><span style="font-size: 85%;">It is my experience looking at lots of environmental data (e.g., groundwater contamination, natural distribution of elements in the environment, river flow data) that many such data are better describer as log-normal than normal distributions. So it may be the case with varves.</span></blockquote><span style="font-size: 85%;">#6 -- Doug Proctor -- August 18, 2010 at 12:12 pm <br />
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<blockquote><span style="font-size: 85%;">BobN suggested “varves” may be better described by log-normal than normal distributions from his work.</span><br />
<span style="font-size: 85%;"><br />
</span><br />
<span style="font-size: 85%;">Varve thickness is controlled by two variables:</span><br />
<span style="font-size: 85%;">1. effective runoff time length, and</span><br />
<span style="font-size: 85%;">2. sediment load.</span><br />
<span style="font-size: 85%;"><br />
</span><br />
<span style="font-size: 85%;">The effective runoff time, i.e. the length of time sediment-carrying waters entered the catchment basin, is itself a function of temperature during the melting or rainfall period of the year, AND the rate of discharge. Below a locally critical rate virtually no sediment will enter the basin even though the streams are running and it is warm. The sediment load is controlled by source area and discharge rate, both affected by temperature, plant growth and precipitation. Bare, cold, dry areas of dirt will make periodic muddy streams when warm, plant covered areas will lead to clear streams. Or warm and dry areas can give periodic muddy streams, and so on.</span><br />
<span style="font-size: 85%;"><br />
</span><br />
<span style="font-size: 85%;">The variables show that there is no unique solution to varve analysis. At the same time, each of those variables is definitely not linear. Temperature and precipitation in the watershed are clearly cyclical but there are step-functions for both. Strong events are periodic but also neither random nor predictable. We are dealing with weather, not climate in the study of varves (similarly tidal cycles have strong weather signatures on top of the lunar cycles).</span><br />
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</span><br />
<span style="font-size: 85%;">You see periodicity in varve changes, which over time is climate. Linearity is not to be expected, but if it occurred would be a nice indication that only one variable was being changed. It would then be up to other lines of thinking to figure out which one it was.</span><br />
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<span style="font-size: 85%;">Engineers find geology crazy-making. All data is soft, and few problems have single solutions.</span></blockquote><span style="font-size: 85%;"> <br />
[<b>UPDATE 2</b> 14 Aug 2011 -- At Bart Verheggen's blog post <i>How science does and does not work (and how skeptics mostly fall in the latter category)</i>, commenter Luminous Beauty <a href="http://ourchangingclimate.wordpress.com/2011/06/22/climate-science-scientific-method-skeptics-not/#comment-13827">critiqued the scatterplots</a> in this post:<br />
<blockquote>Your simple statistics are not so simple. Being able to plug & play into Excel doesn’t necessarily mean you know what you’re about. Log normalization, if implemented properly, is a calibration step, which you keep claiming is impossible. What it does is make the two data sets to be compared orthonormal, or in simple language, proportionately equal, i.e., calibrated to the same scalar mean. Just glancing at your scatter plots indicates ur doin’ it rong.</blockquote>As I understand it, Luminous Beauty's criticism is that the scatterplots should plot the <i>logarithm</i> of each Tiljander data series against temperature anomaly.<br />
<br />
I don't think it makes much difference -- these plots are mainly visual aids, and the observed correlations are spurious in any case. Revisiting the issue, I note that the scatterplots already plot the natural logarithm (ln) of each data series against CRUTEM3v.<br />
<br />
However, XRD is <i>already</i> a logarithmic scale -- "absorbance", not "transmission". Thus, that plot should not have XRD log-transformed. A revised scatterplot follows.<br />
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<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpRy-mF7bk767ddptgGBygaUYRwEvqpLNenpNo2doddtuSDMVFK5Q3jvJtzOFVfhpX083LudnklSoMxVFrIuSPh6TeFAGzSadv97t2FPQoGwsJEEtzTPOtob6eA_k0uJNTb96MEw/s1600/XRD_scatterplot_revised.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="401" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpRy-mF7bk767ddptgGBygaUYRwEvqpLNenpNo2doddtuSDMVFK5Q3jvJtzOFVfhpX083LudnklSoMxVFrIuSPh6TeFAGzSadv97t2FPQoGwsJEEtzTPOtob6eA_k0uJNTb96MEw/s640/XRD_scatterplot_revised.jpg" width="640" /></a></div><div class="separator" style="clear: both; text-align: center;"></div><br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com15tag:blogger.com,1999:blog-7805174.post-11296261670431913962010-08-16T21:00:00.000-07:002010-08-17T16:43:39.189-07:00Part 2: Synopsis of some Tiljander-related arguments<span style="font-size: 85%;">This post is the continuation of a discussion on the Tiljander proxies that took place in the comments thread following the Aug. 1, 2010 <i>Climate Audit</i> post <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/">The No-Dendro Illusion</a>. <br />
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Part 1 is <a href="http://amac1.blogspot.com/2010/08/synopsis-of-some-tiljander-related.html">here</a>. As with that post, I may clean up formatting and grammar here, without notice.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237758">Amac -- Aug 4, 2010 at 1:41 PM</a><br />
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It can be useful to visualize the Tiljander proxies, graphically. <a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/TiljProxies.jpg" rel="nofollow">This JPEG file at BitBucket</a> portrays 20-year averages for Darksum, Lightsum, and XRD (I don’t have Thickness to hand). [For a clearer view, see the charts posted in <a href="http://amac1.blogspot.com/2010/08/tiljander-data-series-data-and-graphs.html">The Tiljander Data Series: Data and Graphs</a>.]<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237864">scientist -- Aug 5, 2010 at 1:17 PM</a><br />
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<span style="color: #660000;">Nice picture. Random thoughts (lot of words and not that much killer insight):</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 1. Looks like pre-1700s, that there is a lot more relative variability of XRD than in LS or RS. Wonder why?</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> Actually reloooking at it, I think this is from the axes and driven by the differences in recent excursion. If we cut off the 1700+ part and then standardized each, they might be comparable.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 2. I admit that XRD seems the more tractable and physically familiar measurement to me than LS or DS. Kind of am biased to using it.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 3. Wonder what is driving the differences in XRD. Is it purely a matter of composition? Higher mineral fraction? Type of mineral? We sure that compaction has no effect? I suspect that some physical insights into what is driving the XRD results would help us with our problem. And just kinda cool to know what is going on physically regardless. I know she does some mag susceptibility and ashing. But maybe quantitative analysis of a few select microtomed sections would help. not the whole core. but some sampling. Just wonder if there is some clue we get from that.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 4. I wonder if some sort of approach to exclude supervarves makes sense. Just to clean things up. Not sure if that happens when a pebble hits the core or when a tree falls in the river coming into the lake or a beaver dams the stream or when a fish dies and falls on the lake bottom. And of course, culling outliers is dangerous. But I just wonder if that kinda screening helps get us a more revealing series.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 5. Are there no significant biological sources of inorganic material? Just wondered. Some of the other studies talk about diatom shells and the like. I have a simple model in my mind of chemically inorganic metal oxides and silicates being the spring melt DS part of the varve, and then chemically organic goo (fish poop or whatever) being the summer stuff that is LS.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 6. Looking at the XRD, looks like there is a big plunge after 1100 and then a different regime from then to about 1700, followed maybe by another from 1800-1950 and then another plunge. Even if you leave aside the post 1700 period, not sure how you explain the phase change from 0-1100 versus 1100-1700 in terms of the typical story of Scandanavian climate. Somethings driving that series. Almost feel like I’m staring at a stock chart (and I hate technical analysis). Really land usage by the nearby population seems more the likely driver? I wonder what is driving the fairly reasonable sized excursions at 20 year intervals as well. With a tree, would think all kinds of biological counfounders could drive it. Would think that the self-averaging in 20 year buckets would eliminate year to to year nuggets from significance. poor resolution of the instrument ought to drive more average of signal. I could see the climate itself having some sort of variability on that timescale, but then the century and millenial scale story doesn’t seem to make sense.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 7. Given that Tilj doesn’t really have any kind of clear climate story on it’s own, midge-man’s comments about “agreeing with Tilj” seem a little off (maybe budd-buddyish?). Your comment on disagreement is more interesting…</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237868">AMac -- Aug 5, 2010 at 2:06 PM</a><br />
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Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237864" rel="nofollow">scientist (Aug 5 13:17)</a>,<br />
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3, XRD drivers: I don’t know. Interesting question, I agree.<br />
<br />
4, supervarve exclusion: I thought of that too, eg Le Chauvanet’s (sp?) criterion. But I suspect it gets ugly fast, esp. with the time-series/red-noise issues tossed in. To me, intuitively, this actually gets to the overconfident and naive approach that the field takes in general, given that most data series are very noisy, and that some probably don’t have any climate (temperature) signal at all. The subject cries out for interdisciplinary work, where the tree-ring people sit at the feet of actual experts and learn, rather than preach.<br />
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5, LS is light-colored minerals (spring runoff) and DS is summertime organics (or perhaps dark-colored clays, I hope Ianl8888 clarifies).<br />
<br />
7, Agree. My point in copy-and-pasting the cites stands–nobody is gainsaying Tiljander03. <b>But</b> the more I stare at her series, the less they look like temperature proxies, or even, more charitably, like temp-and-precip combo proxies. This is a pie in the face for Tiljander03′s interpretations. But before Mann08′s enablers break out the champagne, they should think it through. “<i>Hooray, we didn’t use a genuine proxy upside-down, due to carelessness with modern contamination! Instead, we used a series that’s signal-free noise upside-down, due to carelessness with modern contamination! And it’s the unstated properties of this upside-down noise that extend the validation of our EIV reconstruction from 1500-1850 many additional centuries back!</i>” Hmmm, not good.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237870">scientist -- Aug 5, 2010 at 2:47 PM</a><br />
<br />
<span style="color: #660000;">[snip]</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 7. Yeah, pretty much. What was exciting about Mike’s paper were the new data series, and the potential for sensitivity tests sans tree-rings. But the dependence on Tiljander only (and the failure of CPS and needing EIV is a sign of this, I think) and then the physical problems with Tilj (which look worse than tree rings at this point, to me) make the whole thing pretty weak.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> That isn’t to say that there isn’t something we couldn’t get out of varves in the future. There’s always hope with new things. But neither Mike’s aphysical math-hopper, nor the Finn’s handwaving and level of analysis are getting us there yet. I almost get the feeling, the poor grad students are faced with a really tricky problem and samples that don’t tell a story, and then just try to weave something out of it, to get done and get the union card. The sad thing is that I’m the type who actually thinks all the data collection, physical analysis and even failed correlations are intersting. And I totally respect publication of failed experiments (within reason, but there’s a way to do it that is additive to science). I know the Finns did some hard work and took a swing at a tough problem, but better almost just to publish data and say one doesn’t have a good physical interpretation.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237829">AMac -- Aug 5, 2010 at 1:17 PM </a><br />
<br />
At Gavin’s C-a-s thread:<br />
<br />
#92 Jay Currie Says (August 5th, 2010 at 12:48 am):<br />
<blockquote>…“what about Tiljander? And is it correct to say that if you remove both Tiljander and the dendro you are left with very little of the hockey stick and, worse, the shaft is rather less than straight?…</blockquote>#94 Gavin Says (<a href="http://www.collide-a-scape.com/2010/08/04/gavins-perspective/#comment-12979" rel="nofollow">August 5th, 2010 at 1:42 am</a>):<br />
<blockquote>#92 There are so many false premises and misunderstanding in your ‘logic’ that I don’t even know where to start. I’ll start off with by pointing out that I was just reading the papers concerned and reported what they said – there was nothing new to my comments at all. If other people had not read those papers, that is not my fault…</blockquote>- - - - - - - - - <br />
<br />
<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237893">AMac -- Aug 5, 2010 at 11:36 PM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237855" rel="nofollow">AMac (Aug 5 11:51)</a>,<br />
<br />
Gavin responded to my Collide-a-scape comment #127 at #188. I put the two essays up side-by-side, <a href="http://amac1.blogspot.com/2010/08/two-views-of-tiljander.html" rel="nofollow">Two Views of Tiljander</a>. Also see Brian Eglinton’s earlier remarks of <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237892" rel="nofollow">Aug. 5 at 10:40 PM</a>.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237895">AMac -- Aug 6, 2010 at 12:06 AM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237892">Brian Eglinton (Aug 5 22:40)</a>,<br />
<br />
I put my #127 and Gavin’s #188 side-by-side at my blog, <a href="http://amac1.blogspot.com/2010/08/two-views-of-tiljander.html">Two Views of Tiljander</a>.<br />
<br />
I find that the six points I made to be simple and in a logical sequence.<br />
<br />
1- Mann08′s methods require direct calibration of all proxies to the 1850-1995 temperature record.<br />
<br />
2- Tiljander warned about post-1720 contamination in the Tiljander proxies.<br />
<br />
3- Mann08 considered the warnings, then went ahead and used the proxies.<br />
<br />
4- The 19th and 20th Century contamination was really bad, as a glance at a figure will show.<br />
<br />
5- The correlations that Mann08 thought they found between 1850-1995 temperature and proxy signals were actually spurious correlations to contaminating non-climate signals.<br />
<br />
6- The mistake itself isn’t such a big deal, it’s the refusal to fix the problem that’s the issue.<br />
<br />
<br />
Gavin’s points are, um, lawyerly.<br />
<br />
1- Varve records often contain climate signal, but they can be contaminated.<br />
<br />
2- The Tiljander proxies were 4 out of 1209 proxies used. CPS correlates proxies to local temperature, fixing their orientation. EIV does not.<br />
<br />
3- Mann was very aware of the potentially dubious nature of the modern portion of the Tiljander proxies. So he did sensitivity tests without them as Fig. S8. Fig S8 showed that neither CPS nor EIV is materially affected by including the Tiljander proxies.<br />
<br />
3.1- Without Tiljander, CPS validates back to 400 and EIV validates back to 700.<br />
<br />
4- Regarding Tiljander, Mann08 already showed all there is to show. There is nothing left to do.<br />
<br />
5- All RC statements on Tiljander are correct. If you use neither Tiljander nor tree rings, reconstructions are valid back to 1500 for CPS and as far back as is stated in Mann09′s SI for EIV. All validated reconstructions agree that the 20th Century is anomalously warm.<br />
<br />
<br />
At “The Main Hindrance to Dialog (and Detente)”, Lucia famously noted Gavin’s pronounced tendency to answer questions regarding Tiljander… but to not answer the questions that were actually being asked. Of my six points:<br />
<br />
1- Ignored.<br />
2- Somewhat addressed (cf. “contamination” & “potentially dubious nature”).<br />
3- Tacitly agreed.<br />
4- Ignored.<br />
5- Ignored.<br />
6- Ignored.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237909">AMac -- Aug 6, 2010 at 9:13 AM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237905">Pasteur (Aug 6 07:17)</a>,<br />
<br />
My advice on the Tiljander issue is to work up from the basics.<br />
<br />
Are the data series any good as temperature proxies? (Maybe.)<br />
<br />
Do they have to be directly calibrated, the way Mann08 went about things? (Absolutely, yes.)<br />
<br />
Are they hugely contaminated throughout the 19th and 20th Centuries? (Absolutely, yes.)<br />
<br />
Does this contamination make it impossible to directly calibrate the Tiljander proxies to the 1850-1995 temperature record in any meaningful way (Absolutely, yes.)<br />
<br />
So why all this ducking and weaving about using these proxies? They have to be excluded from all analyses, right? (Absolutely, yes…)<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237752">AMac -- Aug 4, 2010 at 12:55 PM</a><br />
<br />
scientist,<br />
<br />
You see shades of gray when it comes to Mann08′s uses of the Tiljander proxies. Here’s a thought experiment that could lead you to express your ideas more clearly.<br />
<br />
Suppose that you and I are working together on a 1,800 year paleotemperature reconstruction. My job is to find candidate proxies, yours is to calibrate them to the instrumental record, 1850-1995.<br />
<br />
This morning, I say,<br />
<br />
“scientist, I’ve found a reference to four promising 3,000-year-long lakebed sediment records! But there is a big potential problem: the geologists who obtained and characterized the drill cores say that each of the four records has large-scale contamination from 1720 to the present.<br />
<br />
“I know the sources of the non-climate signals: farming and peat-cutting in the lake’s drainage area, local road-building, an episode of bridge reconstruction in the 1960s, and eutrophication (there’s a small city beside the lake).<br />
<br />
“The geologists’ paper says that non-climate influences on the records have grown over the past 280 years, but they don’t offer a quantitative estimate of how the contaminating signals compare to the climate signals. 50% as large? 200%? 1,000%? Who knows?<br />
<br />
“scientist, inclusion of these proxies will make the paper! We <i>really</i> need them!<br />
<br />
<b>“Briefly explain to me in simple, non-technical terms how you think you might calibrate these four sediment data series to the instrumental temperature record, 1850-1995.</b>”<br />
<br />
Indirect and super-duper complex approaches are out: we <i>know</i> from the SI that Mann08′s authors didn’t use them.<br />
<br />
Sadly, then, my response has to be, “It can’t be done.” That ends the thought experiment for me.<br />
<br />
Likewise, it’s over if the answer is “I’ll just ignore the recent history of non-climate contamination.” (I was already aware of that method of producing nonsense correlations.)<br />
<br />
For us to believe that Mann08′s authors <i>might</i> have a logically tenable defense for their choices with the Tiljander proxies, there <i>must</i> be an answer to this thought experiment.<br />
<br />
So, scientist: what’s your suggested approach?<br />
<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237770">Alan S. Blue -- Aug 4, 2010 at 3:38 PM</a><br />
<br />
<span style="color: #274e13;">Re: </span><a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237764" rel="nofollow" style="color: #274e13;">amac78 (Aug 4 14:31)</a><span style="color: #274e13;">,</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> The fundamental disconnect I see is: It seems as if there’s a deep-seated acceptance of the assumption that allows teleconnection. “It’s a valid proxy because our tests of correlation turn out well.” Which is nothing at all like the statement “It’s a valid proxy because we understand the factors involved through causality tests, I can provide a calibration </span><i style="color: #274e13;">and a calibration bias/error</i><span style="color: #274e13;">, and it tests well in an out-of-sample period.”</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> Mann avoids most of that by the reasonable argument “The original authors thought it was a proxy, I’m not an expert on their field, I added it to the pool of potentially useful proxies.”</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> Once you’ve followed the path “Well-correlated implies good proxy,” you’ve already made the assumption that’s fatal to the case. So the argument “That isn’t a good proxy because of reason X” is always trumped by the inherent assumption. “It was discovered by the proxy-finder, so it’s good.”</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> This can be seen in the way “correlation” and “calibration” are used near-interchangeably. And also, really, in the way Mann’s method relegates the vast majority of available proxies to insignificant weights. To the point that there hasn’t been a peep about the “lowest ten” proxies according to Mann in years. Given the paucity and skill of surface measurements even at the height of GHCN, the reasoning for discarding those proxies seems ever fainter as time passes.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237779">scientist -- Aug 4, 2010 at 4:41 PM</a><br />
<br />
<span style="color: #660000;">I’m having a hard time following your thought experiment, including the part where you say I would do various things I wouldn’t do (push for different standards for something because it makes the paper), and then want to know what I say a while longer.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> I think you could,</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 1. treat it like all the rest of the proxies, just plug it into the hopper (I mean if your method has a danger of spurious matches, well… that’s what it has… that’s an issue of the methodology. And there are some safeguards… maybe not as high as you want, but again, this is a separate argument.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 2. Do as (1), but note the physicality concerns in the paper, highlight physicality caveats.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 3. Try to fix it somehow. I would probably avoid that as I don’t know how you fix and it becomes a rathole to go down (in work) if you end up having to do that for every of 1200 proxies. That said, attempts to “fix” like maybe using the pre-bridge years for validation only, might be a method of getting the most signal from noise. Or you could go and do a bunch of work to go to the site and read varveology and get a co-author who understands the issue (or at least consult one) to determine if the confounding is more a 10% issue or a 100% one.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 4. Just not use it. I do think, in this case, it’s important to be fair though. Not to bias your final result because of what makes skeptics happy. (For instance, convert it around and say the Tiljander sediments really drove a high MWP result… and was excluded for the unquantified bridge extents. Do you think everyone on the skeptics side would be happy? Buehler?</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> The extent that you decide which to do, depends on how much you know. If you know the issue the way in your example (and not clear to me that they did), then you need to do something in bucket 2-4 based on some sort of judgment process. I have a hard time answering how to do that. Ideally, you would have everything formalized, and apply it equally to all the series. For instance, saying you intend to use every series of such and such characteristic and then just follow that as a rule. Or if you are going screen things based on physicality (from reading the papers) formalize that.</span><br />
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<a href="http://www.blogger.com/post-edit.g?blogID=7805174&postID=1129626167043191396">SOI -- Aug 4, 2010 at 4:57 PM</a><br />
<br />
<span style="color: #274e13;">Scientist,</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> Of course, Mann didn’t do any of the 4 options you state. He tried to do option 1 (or 2), but erred because he used the series upside down. There is nothing in his code that flips a proxy based on which way would pass testing in the calibration period. Nor did he in the paper, or at any time since, ever provide any reasoning to justify why Tiljander’s interpretation was wrong.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> This is really quite simple -- Mann screwed up. Your attempts to portray this as shades of gray is quite unpersuasive.</span><br style="color: #274e13;" /> <br />
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<a href="http://www.blogger.com/post-edit.g?blogID=7805174&postID=1129626167043191396">scientist -- Aug 4, 2010 at 5:33 PM</a><br />
<br />
<span style="color: #660000;">Maybe so.</span><br />
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<a href="http://www.blogger.com/post-edit.g?blogID=7805174&postID=1129626167043191396">steven Mosher -- Aug 6, 2010 at 2:49 AM</a><br />
<br />
<span style="color: #274e13;">[snip]</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> Absent a cogent argument to wave away the concerns of contamination, a cogent PHYSICAL argument, absent that you are NOT pressure testing Mann’s decision. A cogent pressure test would be this. We have a plausible physical reason to junk the proxy or truncate it. It’s at best questionable and at worst corrupt. If you decide to accept it, you are making a statistical decision with no estimatable probability of being right. Your CI becomes junk overwhelmed by the probability of being wrong about waving away concerns with no basis.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> [snip]</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237827">AMac -- Aug 5, 2010 at 12:56 AM</a><br />
<br />
Re: scientist (Aug 4 16:41),<br />
<br />
Hey, nice response to the thought experiment, scientist.<br />
<br />
1. Yep, you can just take the data series and throw them into the proxyhopper. Mann08′s authors added a few cavils in the text about possible contamination of Tiljander, but besides that, this is what they did, it seems to me.<br />
<br />
2. Highlighting physicality caveats, maybe that helps later if something goes wrong, but what else is it good for? OK, four points awarded for honesty, but minus two for not doing a simple follow-up. As soon as you graph the three series, it jumps out that there’s obviously something very fishy going on with each one, late 1700s on.<br />
<br />
One alone or One & Two together are going to lead to a spurious correlation. So that’s what happened.<br />
<br />
3. Try to fix it somehow. Well we know Mann08 didn’t. If you’re stuck with using a direct approach (cf. splicing), it can’t be done, as far as I can see.<br />
<br />
4. Just not use it. Yep. What you go on to say about “making skeptics happy” is wrong. The need is for <i>predefined selection criteria</i>. The subject is not simple with respect to either practicality or statistics. People in other fields think a great deal about these topics, and develop and revise procedures. Climate scientists, not so much. Their ability to learn useful methodologies from other disciplines, not shown to be high, at this point.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-238060">scientist -- Aug 7, 2010 at 3:01 AM</a><br />
<br />
<span style="color: #660000;">I agree the graph looks ugly, with that recent rise. That concerns more than the big spikes. Gotta think something is going on there, but not sure what. My hypotheses are land use or (lack of) consolidation. When you add the appearance of the huge ramp, and then the things in the text about the contamination, it’s a dubious proxy. I think in terms of the recent Zorita paper, that an expert would likely leave it out. I dunno…a lot of these time series look pretty ugly. Maybe they’re used to that, from that.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> Still… I would not say absolutely contaminated. Even if you feel the concerns are high enough to warrant keeping the series out (and that would be my bet, right now), I would not overstate the case. I think given that we don’t know what the heck is going on with that series physically-chemically, we should not say things like it is absolutely contaminated. I would reserve “absolute” for where we have a higher understanding of the proxy, physically.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237925">scientist -- Aug 6, 2010 at 12:55 PM</a><br />
<br />
<span style="color: #660000;">It’s not clear to me that Mann or Gavin concede the contamination of the Tiljander sediments. Also, when you say “absolutely”, I would say “probably” contaminated. I mean, I haven’t seen chemical analysis to prove contamination. I don’t think we know what chemical substance is in the sediments to give the dramatic LS/DS/XRD modern changes. Not: I’m not arguing that it’s a good proxy. Even a 50% good proxy. Just that it’s an overstatement to say it is 2 plus 2 = 4 contaminated, “absolutely”. I personally don’t know what the heck is going on with those sediments in either old or modern times. I take the info from Tilj as a very serious concern… but then I’m also not blown away by her thoughtfullness or consistency in the paper. Like I still have a bunch of questions on densification (need to look at thichness values…could all this just be a lack of compression for recent varves?) There’s some kind of long term trend from 1700 to present in that data and it’s probably land usage, but I couldn’t say it’s definitely land usage in the way I could say that Lance Armstrong definitely used EPO in 1999 since he had 6 old samples dug out and tested and they came back positive.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> I think that the bigger concern is that the Mannian methods seem to grab anything with a recent ramp in the 20th century and then that basically passes validation (CPS) or gives a good correlation and places into the recon (EIV).* I’m not enough of a statistician to explain what worries me…but it’s something that Zorita would call matching a single degree of freedom (two trends). I don’t really know if the r value handles this, but what I would want is some “wiggle matching”. Like if we detrended each series over the period, would the proxy match the gyrations of temperature? When I look at Cobb’s coral poster and the temperature and the coral, you can pretty clearly see that the coral is “wiggle matching”. Not perfectly, of course, but you can see more than just a match of the long period trend, see some wiggles get matched. I think that Mike does a lot of just matching long trends, so when you get mean on him for the Tiljander, well, he’s all like “that’s how I usually roll”.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> The whole “failure” to admit doesn’t bug me as much as the rest of you, since I don’t think Mike concedes the logic/science as simply as the picture of Amac. What bugs ME is that he wrote that PNAS paper with all the Tiljander stuff (quotes from the paper and all) in the SI. That stuff should have been been in the main paper. Essentially what made the new paper was having more series. But a lot of those new series were questionable (as shown by the quotes). That should have been front and center. And then publish in a more serious, specialized, lower level journal. Not the PNAS ego trip.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> [snip] </span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237955">AMac -- Aug 6, 2010 at 3:48 PM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237925" rel="nofollow">scientist (Aug 6 12:55)</a>,<br />
<br />
> It’s not clear to me that Mann or Gavin concede the contamination of the Tiljander sediments.<br />
<br />
No, they clearly don’t. In my opinion, they aren’t playing by the rules of Science, but by the rules of PostModernScience. The First Rule of PMS is, “there’s no such thing as PMS, we are all upstanding traditional Scientists, and I’m offended that you suggest otherwise!” The second rule is, all the methods of scientific inquiry can be used, as long as they lead to the desired result. If they don’t, all the methods of rhetoric and forensics can also be employed, by our side only.<br />
<br />
As an example of PMS at work, we have constructions about proxy validity like “I don’t know, and it doesn’t matter.” Even a seemingly simple notion like “I don’t know” <a href="http://arthur.shumwaysmith.com/life/content/wheres_the_fraud#comment-9539" rel="nofollow">takes effort to pin down</a>. “It doesn’t matter” hardly needs its own link at this point. Then there is the logic that goes “maybe X, maybe Y. If X then A; if Y then B, so we must go forward weighing both A and B at the same time” (e.g. <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors#comment-9583" rel="nofollow">this subthread</a>). This PMS strategy abandons the reductionist approach; arguments become so complex and confusing that… uh, scientist, what were you saying, again?<br />
<br />
> Also, when you say “absolutely”, I would say “probably” contaminated.<br />
<br />
Either the proxies are “sufficiently uncontaminated to enable a calibration to the temperature signal to be performed, 1850-1995,” or they are “too contaminated to be calibratable.” Now look at the graphs again. Let’s pick Lightsum, the series that more or less means “accumulation of mineral.” You think the 1850-1995 signal has temperature information in it? Really? <b>Really</b>? OK, let’s go back a few centuries and ask Excel for the mean and standard deviation; forget red noise and all that–very simple first-order approximation.<br />
<br />
Century, mean +- SD<br />
15th C, 2.2 +- 0.6<br />
16th C, 1.9 +- 0.7<br />
17th C, 2.2 +- 0.7<br />
18th C, 2.4 +- 0.9<br />
19th C, 4.8 +- 2.0<br />
20th C, 9.4 +- 8.0 (thru 1985)<br />
<br />
[I have expanded this analysis and charted the results in <a href="http://amac1.blogspot.com/2010/08/tiljander-data-series-data-and-graphs.html">The Tiljander Data Series: Data and Graphs</a> -- AMac]<br />
<br />
So you, Gavin, Mia, and I agree that from prior to the 15th Century through ~1720, Lightsum might — <i>might!</i> — contain a temperature signal.<br />
<br />
Mia and I look at those 19th and 20th Century numbers and say, “Yikes! Those numbers are huge and variable! And they are huge and variable in a way that they just weren’t, in the 15th, 16th, 17th, even the 18th Centuries! Whatever temperature signal is in there, it’s overwhelmed by a deluge of contamination!”<br />
Gavin looks at those numbers and says, “Hmmm, ‘<b>possible</b> anthropogenic contamination’ in more recent centuries, so ‘potentially useful, but also <b>potentially</b> dubious’. Let’s use ‘em and see what happens!”<br />
And you’re going with Gavin on this, because, despite these ugly numbers, despite the graph that’s level for centuries before going hyperbolic in the 20th Century, despite the obvious impossibility of meaningful calibration 1850-1995, despite the chapter-and-verse of roadbuilding, peat cutting, farming, bridge reconstruction, and eutrophication — I used the word “absolutely.” Without a clear-cut chemical signature for this hypothesized, so-called “contamination.”<br />
<br />
> but then I’m also not blown away by her thoughtfulness or consistency in the paper.<br />
<br />
OK, you convinced me of that. Now I wonder whether Lightsum and the rest are any sort of temperature proxy at all, because maybe Tiljander et al were scraping the bottom of the interpretation barrel. Um, <i>that’s not an endorsement of Gavin’s position!</i> Having a reconstruction whose validity is improved by adding upside-down (with respect to Tiljander03) <i>noise</i> isn’t better than having that validity bulked up by reliance on upside-down (with respect to Tiljander03) signal…<br />
<br />
Are you <i>sure</i> you don’t want to change your vote?<br />
<br />
> I think that the bigger concern is that the Mannian methods seem to grab anything with a recent ramp in the 20th century and then that basically passes validation (CPS) or gives a good correlation and places into the recon (EIV).<br />
<br />
Well that is something of a problem, and I can think of four or so examples offhand.<br />
<br />
> what I would want is some “wiggle matching”.<br />
<br />
Agree, especially now that we’ve seen some.<br />
<br />
> The whole “failure” to admit doesn’t bug me as much as the rest of you, since I don’t think Mike concedes the logic/science as simply as the picture of Amac.<br />
<br />
I understand that Prof. Mann doesn’t concede anything to my view. That explains <i>his</i> conduct, but it hardly justifies anybody else’s. If he decides that the moon is made of green cheese and Apollo 11 be damned, will PNAS’ editors send that paper out to peer review, and publish it? Will Gavin then declaim, “I don’t know, and it doesn’t matter”?<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-238113">AMac -- Aug 7, 2010 at 9:37 AM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-238061" rel="nofollow">scientist (Aug 7 03:07)</a>,<br />
<br />
> I agree the graph looks ugly… My hypotheses are landuse or (lack of) consolidation… it’s a dubious proxy… I would not say absolutely contaminated… I would not overstate the case… we don’t know what the heck is going on with that series physically-chemically, we should not say things like it is absolutely contaminated. I would reserve “absolute” for where we have a higher understanding of the proxy, physically.<br />
<br />
I agree narrowly but not broadly with your general thrust here. You’re being nice, and it’s nice to be nice, but we also have to remember that guy Feynman, who was eccentrically charming but <i>didn’t</i> approach technical issues in terms of the importance of being agreeable with our scientific betters.<br />
<br />
You’d have the basis for making a reasoned argument if Mann08′s authors and champions would offer some justification for the idea that Lightsum (to stick with that example) is a plausible temperature proxy. Then we could go back and forth, a “preponderance of the evidence” discussion. But <b>Prof. Mann</b> ducks the question, preferring to describe the fossil fuel lobby’s anti-Mann conspiracy; listen to Chris Mooney’s painfully fawning podcast interview if you’re feeling cruel (link at my blog). <b>Co-authors</b>, “Maintaining radio silence, sir!” When <b>Gavin</b> pronounces, how much prep work does he have to put into those legalistic turns of phrase and lawyerly grammatical ambiguities, do you think? <b>Mann08's other defenders</b> are flyweights on this issue (name one who isn’t?).<br />
<br />
So please take “absolutely” as my shorthand for “overwhelming evidence at this point that post-1720 Lighsum is invalid as a proxy for temperature, with no plausible rationale on offer that post-1720 Lightsum <i>might</i> be an acceptable temperature proxy (although new theories and evidence might change this picture).”<br />
<br />
Saying you don’t like “absolutely” doesn’t cut it. You have to (1) Dispute the multiple lines of reasoning that each show Lightsumm to be an unacceptable temperature proxy (er, you’ve <i>added</i> to the pileup!), or (2) Propose a hypothesis by which Lightsum is (or might be) an acceptable temp proxy. Remember, the big piece of gristle here is that for Mann08, “acceptable” means “directly calibratable to the 1850-1995 CRUTEM3v record.”<br />
<br />
PMS adepts loathe Occams Razor, but I kinda like it. WWWilliamS? “Dubious”? Hardly–that’s a pleasant euphemism. “Must discard?” Yep.<br />
<br />
> the thing got through peer review without anyone worrying about Tiljander… I think the review was fine.<br />
<br />
I’d be interested in seeing the peer reviews and editors’ comments on Mann08. I have a pretty clear suspicion as to what they looked like, and it doesn’t map to yours. This was a shallow, perfunctory review process, “Yeah, looks good to me, <strike>my buddy Mike</strike> <i>the eminent Dr. Mann</i> has once again contributed a brilliantly important synthesis. ‘Korttajärvi’ is misspelled as ‘Korttajarvi’ on page 6; this must be corrected.”<br />
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That will wrap up this synopsis of part of the very long comment thread at "The No-Dendro Illusion."<br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com0tag:blogger.com,1999:blog-7805174.post-48631728242470599852010-08-10T19:32:00.001-07:002010-08-10T19:32:47.564-07:00Unthreaded postThis is a post for comments that don't fit anywhere else on the blog.<br />
<br />
Please be civil, etc.AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com59tag:blogger.com,1999:blog-7805174.post-83153169232065579212010-08-10T18:29:00.000-07:002010-10-28T16:16:40.521-07:00Synopsis of some Tiljander-related arguments in a recent Climate Audit thread<span style="font-size: 85%;">This post is a placeholder that will hopefully be superseded by a more careful and thorough description of a discussion of the use of the four Lake Korttajarvi lakebed sediment series (the "Tiljander proxies") in Mann08 (PNAS). This discussion was largely between two pseudonymous commenters at Steve McIntyre's <i>Climate Audit</i> post <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/">The No-Dendro Illusion</a>. <br />
<br />
I'm putting this together to respond to <a href="http://deepclimate.org/2010/07/19/open-thread-4/#comment-4922">this recent comment</a> by DeepClimate, at his blog.<br />
</span><br />
<a name='more'></a><span style="font-size: 85%;"><br />
Note that I have assembled this version of the Climate Audit thread to highlight the scientific issues concerning Tiljander that were being debated. I've corrected some typos, altered some formatting, and snipped remarks that I didn't think were central to the main thrust of the discussion. Of course, the original remains a click away. If I've mangled any comments or left out any key thoughts, please make a note in the comments.<br />
<br />
(In this rough-draft post, I expect there are more typos and formatting errors, and that I'll want to make some content additions and changes. I reserve the right to do these things, without notice. When things settle down, I will put strikes through the relevant sentence.)<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237497">amac78 -- Aug 2, 2010 at 11:40 PM</a><br />
<br />
The fundamental problem with Mann08′s use of the four Tiljander proxies is this: <br />
<br />
1. Mann08′s methods absolutely require that proxies be calibrated to a gridcell derivation of the instrumental temperature record, 1850-1995.<br />
<br />
2. The Tiljander proxies cannot be properly calibrated to the instrumental temperature record, because non-climate local factors progressively overwhelm any climate-related signals, in the 19th and 20th centuries.<br />
<br />
3. Mann08′s authors mistakenly set aside the Tiljander03 authors’ warnings of contamination, and performed a set of four faux [sic -- substitute "nonsense" -- AMac] calibrations. 1850-1995, the major influences on the varve series were nearby agricultural activities, roadbuilding and bridge reconstruction, and lake eutrophication. These activities caused Darksum, Lightsum, X-Ray Density, and Thickness to increase during the screening and validation periods. The gridcell temperature anomaly calculated by CRUTEM3v also increased during those periods, leading to positive correlations between proxy values and temperature. The correlations of Darksum, Lightsum, and Thickness were judged sufficiently high to be Significant (XRD’s correlation was lower).<br />
<br />
All four correlations are meaningless in that they have nothing to do with any <i>causal</i> relationship between any climate-related factor and any proxy-related characteristic. A trivial consequence of this procedure is that Mann08′s authors unwittingly assigned meanings to Lightsum and XRD that were opposite in orientation to the assignments proposed by the only relevant authorities, Mia Tiljander and the co-authors of her <i>Boreas</i> paper in 2003.<br />
<br />
[AMac note (10/28/10) -- I was mistaken to take Mann08's authors word for it, and talk about the "<i>four</i> Tiljander proxies." There are only three, as "Thickness" is simply "Darksum" plus "Lightsum". More exactly, Tiljander derived "Darksum" by subtracting "Lightsum" from "Thickness." Either way one looks at it, the degrees-of-freedom argument is the same. See the first graph in the post <a href="http://amac1.blogspot.com/2010/08/tiljander-data-series-data-and-graphs.html">The Tiljander Data Series: Data and Graphs</a>.]<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237498">amac78 -- Aug 2, 2010 at 11:52 PM</a><br />
<br />
Links to the Tiljander et al (<i>Boreas</i>, 2003) paper, other primary literature, and data archives are <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html" rel="nofollow">here</a>.<br />
<br />
This <a href="http://amac1.blogspot.com/2010/03/newly-discovered-jarvykortta-proxy-ii.html" rel="nofollow">“Jarvykortta Proxy” post</a> walks through Mann08′s faux [sic -- substitute "nonsense" -- AMac] calibration of the XRD proxy.<br />
<br />
<a href="http://amac1.blogspot.com/2010/06/ari-jokimaki-looks-at-tiljander-proxies.html" rel="nofollow">This post</a> contains the temperature anomaly that CRUTEM3v calculated for the 5 degree x 5 degree gridcell that includes Lake Korttajarvi.<br />
<br />
Arthur Smith’s post <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors" rel="nofollow">Michael Mann’s errors</a> (now closed to comments) contains the most accessible layperson’s discussion of Mann08′s use of the Tiljander proxies. The best arguments of the pro-Mann08 bloggers are on display there, for what they are worth.<br />
<br />
Lastly, Gavin Schmidt, Michael Mann’s co-blogger at RealClimate.org, called me out at Collide-a-scape, in the guest post <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/" rel="nofollow">The Main Hindrance to Dialogue (and Detente)</a>. His best arguments are there, for what that is worth.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237383">AMac -- Aug 2, 2010 at 8:30 AM</a><br />
<br />
I have made an effort to record <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html" rel="nofollow">literature citations</a> and <a href="http://amac1.blogspot.com/2009/11/blog-links-mann-08-and-korttajarvi.html" rel="nofollow">blog posts</a> that discuss the use of the Lake Korttajarvi (Tiljander) lakebed sediment records in Mann08 (PNAS). The compilations may be useful to newcomers to this story.<br />
<br />
Mann08 considered four measures that Tiljander and her co-workers derived from their lakebed sediment drill cores. Thus, there are <i>four</i> Tiljander proxies. Two of them are miscalibrated and “upside-down,” one is miscalibrated and rightside-up, and one is miscalibrated and of indeterminate orientation. Thus, <i><b>miscalibration</b></i> rather than <i>upside-downedness</i> is the core (heh) issue.<br />
<br />
I have walked through the precise issues with Mann08′s employment of one of the two upside-down proxies, X-Ray Density, in the post <a href="http://amac1.blogspot.com/2010/03/newly-discovered-jarvykortta-proxy-ii.html" rel="nofollow">The Newly Discovered Jarvykortta Proxy — II</a>.<br />
<br />
For an exhibit of the best current AGW Consensus arguments in favor of Mann08′s uses of the Tiljander proxies, see the (ongoing) comment thread of Arthur Smith’s post, <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors" rel="nofollow">Michael Mann’s Errors</a> (while a supporter of the AGW Consensus, Arthur has done a commendable job as an ‘honest broker,’ allowing all parties to have their say.)<br />
<br />
Within that thread, my comment <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors#comment-9979" rel="nofollow">“It’s certainly helpful to…”</a> describes the three proxies’ assignments in Tiljander03, and contrasts them with the assignments for them in Mann08. (A climate-related discussion of the fourth Tiljander proxy, “Thickness,” was not provided in Tiljander03. Thus, Mann08′s use of it cannot be “upside-down” or “rightside-up” with respect to the earlier authority’s interpretation.)<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237696">Jarkko -- Aug 4, 2010 at 4:36 AM</a><br />
<br />
<span style="color: #274e13;">Can I suggest something? Take a look at Google Earth. The Street View gives you a good impression of the surrounding enviroment. I live pretty close to Lake Korttajarvi. The bridge doesn’t cross the lake, but the river running into it. The lake is right next to the town of Jyvaskyla, population 130,000.<br />
<br />
The coordinates of the lake are 62°20’16.10″E and 25°41’30.14″N.<br />
<br />
This recently puplished academic dissertation finds some support for the interpretation of the proxies by Tiljander:<br />
<br />
T.P. Luoto. "Spatial and temporal variability in midge (Nematocera) assemblages in shallow Finnish lakes (60−70 °N): community-based modelling of past environmental change." Helsinki University Press, 2010. <a href="https://oa.doria.fi/bitstream/handle/10024/60654/spatiala.pdf?sequence=1">PDF</a>.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237771">scientist -- Aug 4, 2010 at 3:46 PM</a><br />
<br />
<span style="color: #660000;">1. [snip]<br />
<br />
2. I skimmed the midge thesis you referred me to. Can you please identify what parts of the thesis validate “the Tiljander thesis”? Page number? We are talking about two 70 page documents!<br />
<br />
3. And does the midge thesis validate the bridge concern, or Tiljander’s overall qualitiative comparison of her core to Roman Warm Period and such?</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237821">AMac -- Aug 4, 2010 at 10:54 PM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237771" rel="nofollow">scientist (Aug 4 15:46)</a>, <br />
<br />
> 2. I skimmed the midge thesis, you referred me to. can you please identify what parts of the thesis validate “the Tiljander thesis”? <br />
<br />
Thanks for the opportunity to clarify. I wrote,<br />
</span><br />
<blockquote><span style="font-size: 85%;">It’s highly likely that Tiljander03′s overall interpretations of the Lake Korttajarvi data series as climate proxies pre-1720 are generally correct. Tiljander and her advisor and co-authors are the sole ‘local’ authorities; their views are consistent with other paleolimnologists’. E.g. … Tomi Luoto’s repeated citations of Tiljander03 in his 2010 dissertation [on fossil midges]…</span></blockquote><br />
<span style="font-size: 85%;">Luoto cites Tiljander et al (2003) seven times. Using the MS pages (not the PDF paging) –<br />
<br />
p. 38, “Tiljander et al. (2003) noted from annually laminated lake sediments from southern Finland that during two phases, ca. 1580-1630 and 1650-1710 AD, a colder climate prevailed.”<br />
<br />
p. 38, “The study of Luoto et al. (2008) also suggested that the LIA was not uniformly cold… which was consistent with the results of Tiljander et al. (2003).”<br />
<br />
p. 39, “the LIA was characterized by wetter climate conditions (Tiljander et al. 2003)…”<br />
<br />
p. 42, “The maximal inferred water depth value occurred in Lake Iso Lehmälampi ca. 1700 AD, which is consistent with the results of Tiljander et al. (2003), who suggested wetter climatic conditions at that time.”<br />
<br />
p. 42, “The coolest time period of the LIA occurred ca. 1700 AD in southern Finland (Tiljander et al. 2005; Fig. 14)…”<br />
<br />
p. 43, “The oxygen levels in Lake Iso Lehmälampi experienced a major increase around 1700 AD, occurring simultaneously with the coldest period of the LIA in southern Finland (Tiljander et al. 2003; paper II).”<br />
<br />
p. 45, “The results of Tiljander et al. (2003) from the central part of the country [indicate that] the LIA was a wetter climatic episode in Finland. <br />
<br />
These cites do not, of course, “validate Tiljander”–nor was that my claim. They address a narrower but still worthwhile question: how are Saarinen, Tiljander, Saarnisto, and Ojala viewed by relevant paleolimnologists? Are their views outliers; are their results discounted due to sloppiness, or unreliability, or a history of unfounded speculations? Here, we see Prof. Salonen of the University of Helsinki,apparently comfortable with his student Tomi Luoto citing Tiljander03 as an authority for characterizing the Little Ice Age (ca. 1550-1850) as being a variably colder, wetter period in southern Finland.<br />
<br />
Are there opposing interpretations from these or other records that suggest something different, e.g. that contest Tiljander03 on climate regimes in southern Finland over the past centures? Judging from this sample, that does not seem to be the case.<br />
<br />
> 3. And does the midge thesis validate the bridge concern or Tiljander’s overall qualitiative comparison of her core to Roman Warm Period and such?<br />
<br />
No. I wasn’t anticipating such validation. Looking now, I don’t see any.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237825">AMac -- Aug 5, 2010 at 12:23 AM </a><br />
<br />
Regarding another question scientist asked (somewhere else on the thread, earlier today) — Here’s something pretty interesting. <br />
<br />
I just looked at Fig. 14 of TP Luoto’s dissertation on pg. 36; it includes a water temperature graph of Lake Hamptrask, Finland (just northeast of Helsinki) from about 1350 to the present. It’s inferred from fossil Chironomids. There’s a pretty clear dip where the Little Ice Age should be. From Fig. 5, Lake Hamptrask is about 270 km south of Lake Korttajarvi. At Bitbucket.org, I’ve uploaded a file that shows three Tiljander proxies (Darksum, Lightsum, XRD; 20-year averages, oriented per Tiljander03) and the Luoto proxy (image reversed and rotated from the dissertation).<br />
<br />
The file is <a href="https://bitbucket.org/amac/tiljander-proxy-graphs/downloads/TiljHamptrask.jpg">TiljHamptrask.jpg</a> ... All three Tiljander proxies are contaminated post ~ 1750, but that still leaves ~400 years to compare with Luoto’s record. To me, none of the Tiljander records seem to say much about climate changes (e.g. temperature or precipitation) going into the LIA.<br />
</span><br />
<div class="separator" style="clear: both; text-align: center;"><span style="font-size: 85%;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_DITtedQXDlE4I53K9rF-dJMAOL12TWW43RJunurbGFLSQAf80qmynTcY-EtnQgA68uPC-53LdzQ_R8NFJMPkbQstrUvNPdGJYXfaXrsODHVaeUxF8OzijLQv7roydokxx0ERxg/s1600/TiljHamptrask.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_DITtedQXDlE4I53K9rF-dJMAOL12TWW43RJunurbGFLSQAf80qmynTcY-EtnQgA68uPC-53LdzQ_R8NFJMPkbQstrUvNPdGJYXfaXrsODHVaeUxF8OzijLQv7roydokxx0ERxg/s640/TiljHamptrask.jpg" width="320" /></a></span></div><span style="font-size: 85%;">Flipping Lightsum or XRD to make them match with Mann08 instead of Tiljander03 doesn’t help matters.<br />
<br />
Of course this is a comparison of trends from places 270 km apart, one near the Gulf of Finland, but still. The LIA was supposed to be a widespread phenomenon.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237832">scientist -- Aug 5, 2010 at 1:31 AM</a><br />
<br />
<span style="color: #660000;">Very pretty graphs. Just shooting from the hip, but:</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 1. independence</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> -boy LS and DS seem very anticorrelated. Not perfectly, but pretty close.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> -And then LS and XRD are anticorrelated as well (graph of XRD is inverted axes).</span><br style="color: #660000;" /><span style="color: #660000;"> -Makes it look like there’s one primary variable in all 3 series.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 2. Agreed, you don’t see that LIA-posited dip from Luoto on the XRD.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 3. That 1300 excursion in the Tilj series are interesting as well. Was that one super varve driving the whole 20 year block so out of whack? Wonder how she discusses it.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237839">AMac -- Aug 5, 2010 at 7:58 AM</a> <br />
<br />
[snip]<br />
<br />
> 1. Independence<br />
<br />
Note that I plotted LS upside-down (heh) to follow Tiljander03′s convention; her “warmer” is towards the top of the graph. XRD as well.<br />
<br />
> 2. Luoto<br />
<br />
Agreed. We see a ‘clean’ proxy series and go, “aha.” (1) LIA, (2) No 19th/20th Century craziness, where the lakes hafta be hot tubs in the winter or ice-crusted in the summer (depending on which way you orient the graph).<br />
<br />
> 3. Yep, one super-varve! [in 1326]<br />
<br />
<table align="center" border="1" cellpadding="1" cellspacing="0"><tbody>
<tr><th>Year A.D.</th><th>Lightsum (mm)</th><th>Darksum (mm)</th></tr>
<tr><td>1324</td><td>0.56</td><td>0.96</td></tr>
<tr><td>1325</td><td>0.56</td><td>1.14</td></tr>
<tr><td>1326</td><td>6.10</td><td>12.86</td></tr>
<tr><td>1327</td><td>0.51</td><td>0.58</td></tr>
<tr><td>1328</td><td>0.47</td><td>0.72</td></tr>
</tbody></table><br />
[AMac note 10/28/10 -- Varve values converted to millimeters for ease of interpretation]<br />
<br />
A piece of melting, dirty ice that dropped some muck right at the drill site? A hurricane that summer? Chariots of the Gods?<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237841">PaulM -- Aug 5, 2010 at 8:03 AM</a><br />
<br />
<span style="color: #274e13;">Of course, the series are not independent, and there is really only one variable. That’s immediately clear from the Tiljander paper or the Mann SI. Only a fool would attempt to use these as four independent proxies.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> Correction: LS and DS are correlated, not anti-correlated.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> This means that the interpretation of Tiljander et al (DS=Temp, LS=-Temp) does not make much sense.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> In a more recent Finnish paper (see Aug 5, 2010 at 9:30 PM post) LS, DS and thickness are all interpreted as -Temp.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237831">scientist -- Aug 5, 2010 at 1:20 AM</a> <br />
<br />
<span style="color: #660000;">My gut feel is they are not good for much also…or at least Tiljander hasn’t really figured out a way to extract much of a story from them. she had a lot of comments about how her stuff compared to other papers in the RWP [sic: Medieval Warm Period], but I got more the sense, she was reading those papers and then saying “oh…my series corresponds), than that she was really looking at the series, asking what to do they tell me on their own, pause, then compare and contrast to previous work.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> I guess you could read and see what she says in Boreas about LIA…</span><br style="color: #660000;" /> <br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237843">PaulM -- Posted Aug 5, 2010 at 9:30 AM</a> <br />
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<span style="color: #274e13;">A more recent relevant paper is:<br />
<br />
Haltia-Hovi et al (2007), "A 2000-year record of solar forcing on varved lake sediment in eastern Finland." Quaternary Science Reviews Vol. 26, p 678-689. [PDF via <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html">"Primary Links" post</a>.]<br />
<br />
The data from this paper (as well as Tiljander) was originally used upside-down by Kaufmann et al (2009), see Steve McI's post on the Kaufmann Corrigendum. In the Kaufman SI update correction they say “Record 21 was corrected to reflect the interpretation of Haltia-Hovi et al. (S33) that varve thickness is related inversely to temperature” (it is amazing that Mann continues to deny this after Kaufmann et al have acknowledged it). This paper has some advantages over the earlier Tiljander et al one. There were 8 cores (rather than 2) and there is less of an issue with recent human interference (more remote area). The 8 cores show a consistent picture. They say that thickness and DS are very highly correlated (r=0.99) and it looks like LS is also positively correlated with these. They interpret these as being inversely correlated with temperature. I think the argument is partly that when the lake is frozen over, stuff settles out more easily. They say MWP and LIA are ‘subtly recorded’ by the varves.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237602">scientist -- Aug 3, 2010 at 2:49 PM </a><br />
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<span style="color: #660000;">Some general impressions [from reading through Tiljander's Boreas paper, most of Mann08, and skimming Tiljander's thesis].</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> - Seems like the parties agree that the no-tree chronology is dependent on the Tiljander proxies.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> - Mann seems to have had an overly simple conception of the Tiljander series (bigger number=thicker layer=warmer year). The actual proxies were not just thicknesses, but measures of content.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> - Thus, he likely used theses series without enough understanding of their limitations.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> - So he probably at a minimum, should have informed the readers than his chronology was dependant on a new geo-isolated set of proxies and that they were themselves debatable. (But I think his failure was a mistake, not duplicity.)</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> - I would be interested if he thinks the varve series are “good”, “debatable” (i.e. equivalent to the [bristlecone pine series]), or completely unsuitable.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> Some more general impressions:</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> - Not impressed with the Tiljander work in terms of a decisive explanation of the sediments. She does not construct a temperature series. Has a LOT of qualitative references to other studies and comparisons like ‘a lot of gray in period X’ rather than numerical, statistical statements.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> - I don’t understand (this may be my limitation) the issue of LS, DS and XRD and wonder if they are all independant or how they would be physically resolved to show exactly from a compositional standpoint (both content and overall density) how these measures are driven. IOW, you have really 2 metrics: physical density and inorg/organic fraction. No?</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> - I’m concerned about the issue of compaction. How is this addressed? (and if this was addressed in a comment within one of the 20 different blog threads, this is not my “bad” for not reading it, it’s a flaw in having to weed though so much spinach to find the meat.)</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> [snip]</span><br style="color: #660000;" /> <br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237869">Jarmo -- Aug 5, 2010 at 2:16 PM</a><br />
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<span style="color: #274e13;">I read the Tiljander paper and she is quite clear about the anthropogenic influences. </span></span><br />
<br />
<span style="font-size: 85%;"><span style="color: #274e13;">On page 9 she noted, </span><span style="color: #274e13;"> “The lake was quite badly polluted by waste waters in the 20th century, but since the loading of polluted waters stopped in the late 1970’s, the quality of the water has improved.”</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> And on page 24, </span><span style="color: #274e13;"> “Since the early 18th century, the sedimentation has clearly been affected by increased human impact and therefore not useful for paleoclimate research.”</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> Tiljander may or may not have been aware that Lake Korttajärvi was partially drained by farmers and two smaller lakes were drained completely upstream. This was a common practice in Finland in the 18th and 19th centuries to create new farmland. The geological survey of the area (</span><a href="http://www.gtk.fi/data/mps/321206.pdf" style="color: #274e13;">PDF, in Finnish, with maps</a><span style="color: #274e13;">) does not state how much the water level dropped.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237614">amac78 -- Aug 3, 2010 at 3:22 PM</a><br />
<br />
Re: scientist (Aug 3 14:49),<br />
<br />
[These are the central issues:]<br />
<br />
1. The procedures in Mann08 for both CPS and EIV absolutely require calibration of all proxies to the instrumental temperature record, 1850-1995.<br />
<br />
2. None of the four Tiljander proxies used in Mann08 can be meaningfully calibrated to the instrumental temperature record, the result of progressive contamination of any climate signals during the 19th and 20th centuries by local activities (farming, peat cutting, road building, bridge reconstruction, lake eutrophication).<br />
<br />
3. Therefore, Mann08′s uses of the Tiljander proxies rely on <strike>faux</strike> <i>spurious</i> calibrations. <br />
<br />
[Note: My term "faux" was challenged <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237637">by Spence_UK</a> as poor usage. I amended it later to "spurious" on the strength of a this 1926 statistics paper by Yule (<a href="http://www.math.mcgill.ca/%7Edstephens/OldCourses/204-2008/Handouts/Yule1926.pdf">PDF</a>), though "nonsense correlation" seems yet better. MikeP noted <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237693">Aug 4, 2010 at 2:32 AM</a><br />
</span><br />
<blockquote><span style="font-size: 85%;">...Yule actually distinguished between “nonsense” correlations – correlations which exist between two quite unrelated variables as in the 1926 paper, and “spurious” correlations which he had identified in 1897 – where two variables are related but only because they both depend on a third variable which is not being considered.</span></blockquote><span style="font-size: 85%;">-- AMac] <br />
<br />
[snip]<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237638">scientist -- Aug 3, 2010 at 4:56 PM</a> <br />
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<span style="color: #660000;">My impression (and I’m being honest about my level of knowledge as an outsider trying to decide fairly) is that Tiljander stuff is at a minimum questionable. I don’t think Tiljander can really explain the sediments herself, so it’s not a no-brainer in terms of “only her word counts”, but that her comments need to be taken very seriously. I would probably fall in the camp of “nobody has a good handle on what that series means. I just did not think the Boreas paper was good…way too hand-wavey…and then of course Mike hasn’t even addressed the physical issues at all. Then when you add in that this field seems even more new and evolving than tree rings? If essentially all varveologists (maybe those not Finn group) agree that the samples belong in the “complete junk” category, then I’d be inclined to take the appeal to authority. [Otherwise, I'm forced to read all the references to methodology from Tiljander's paper, get a textbook, etc. to drive myself out of the middle bucket.]</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> And that to use the series, since they were so crucial to the result, Mike should have disclosed the dependence of results on that proxy particularly, his different usage versus the data collector, etc.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> I’m also a little concerned by some other issues.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 1. That a substantial part of his paper’s new results depend on one set of geographically isolated samples (even if they were in the “good” bucket)! It’s one place in Finland!</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 2. That CPS doesn’t work.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 3. And that the samples passed correlation screening (does this mean that the tests aren’t tough enough (not enough wiggle matching, joining two linear trends? And I admit to not knowing how to settle this statistically, just highlighting a question). OR does it mean, that really Tilj was WRONG to think that one could not get a real temp chronology out of the samples and too timid and should have taken a swing at it instead of being dissuaded by that 1999 farmer’s comment? Even if so, it still seems that Mike ought to then publish his own paper, just on Lake K.’s sediments, using Tiljander’s data, but giving a different interpretation.</span><br style="color: #660000;" /> <br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237641">Steve McIntyre -- Aug 3, 2010 at 5:34 PM</a><br />
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<span style="color: #274e13;">You’re totally missing the problem of the contamination of the sediments by non-climatic factors such as bridge-building. Tiljander stated clearly that the sediments were contaminated in the modern period. The problem with Mann et al was that they ignored this warning.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> This is an entirely separate issue from whether the sediments meant anything in the earlier period either. There are a number of posts at the site about varve-ology, in which individual sites used in Kaufman et al (2009) were examined. But that’s an entirely different issue from the very simple one about Mann’s correlation of sediments from Finnish bridge building with global climate fields – something that may qualify as a classic example of spurious correlation, up with Yule’s original alcoholism and Church of England marriages.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237670">Ed Snack -- Aug 3, 2010 at 8:34 PM</a><br />
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<span style="color: #274e13;">[snip]</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> On Tiljander (the proxies that is) I suggest you’re trying too hard. We have only one set of data and there’s no other source (as far as we know) available. To attempt to justify the inclusion of this data in a way contrary to our only source must surely require at least some form of proof, be it only a logical argument based on some physical mechanisms. I assert you cannot make any scientific claim for the inclusion based on the matching of patterns via a mathematical method without some underlying explanation. Otherwise it is just as valid to claim that the increasing trend in UK marriages (say) between 1900 and 1970 (again, for example) can be calibrated against some other set of data and hence represents a valid temperature proxy.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> Do you think it reasonable for the standard of inclusion to be “it’s OK unless you can prove otherwise” on questionable data?</span><br style="color: #274e13;" /> <br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237683">scientist -- Aug 3, 2010 at 11:15 PM</a><br />
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<span style="color: #660000;">There are zero perfect proxies. Would you eliminate them all? I don’t think all should be included or all excluded. This is a tricky issue. You lot should not try to get rid of the stuff you don’t like extra hard, nor should Mann do the reverse. I made my three buckets as a sort of simplification of what is a spectrum. </span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> I think at a minimum, the physical concerns with Tiljander should have been better known by the authors and discussed in paper, especially given the crucial role they have for the early no-dendro EIV recon. Perhaps they don’t belong in at all, but I don’t know enough to say that right away. I mean some here want to get rid of the [bristlecone pines]…but it’s at least possible (maybe even plausible) that they are responding to temps and have done so for a while (the opportunistic trial of sheeps, dry lakebeds, barktype, precip, bad sample versus resample (Ababneh), etc. came across as a willingness to believe in anything wrong with the proxy in a rather hopeful way to get rid of them. Similar behavior with Gaspe.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> I think you need to be careful not to use bad stuff or to be prone to grabbing series to support a point of view (Mann, maybe), but also wary of skeptics trying to go after whatever proxies they can with selective criticism. It’s a type I/II issue. You can have a false negative and a false positive. Can screen in bad stuff or screen out good stuff.</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237685">Steve McIntyre -- Aug 3, 2010 at 11:44 PM </a><br />
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<span style="color: #274e13;">For something to be a “proxy”, it has to be shown to be a proxy. Something doesn’t become a “proxy” merely by being a time series.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> If a “proxy” is supposed to be uniquely important, then you should be sure that you understand whether its behavior is properly understood.</span><br style="color: #274e13;" /> <br style="color: #274e13;" /><span style="color: #274e13;"> [snip]</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237642">amac78 -- Aug 3, 2010 at 5:34 PM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237638">scientist (Aug 3 16:56)</a>,<br />
<br />
> I don’t think Tiljander can really explain the sediments herself<br />
<br />
I’m not sure what you expect. From what I can see, that paper is about on a par with similar ones. Hank Roberts had a neat link to a report of German lake whose sediments clearly recorded the Younger Dryas, but that was a pretty drastic change of climate regimes (and it’s behind Nature’s paywall). For context from 5 other Finnish lakes, pull Jarmo’s PDF.<br />
<br />
> so it’s not a no-brainer in terms of “only [Tiljander's] word counts”, but that her comments need to be taken very seriously.<br />
<br />
Agreed.<br />
<br />
> [Prof. Mann] hasn’t even addressed the physical issues at all.<br />
<br />
Agreed.<br />
<br />
> Otherwise, I’m forced to read all the references to methodology from Tilj’s paper, get a textbook, etc. to drive myself out of the middle bucket.<br />
<br />
Try looking at the graphs of XRD in the Korttyjarva River post. For Mann08′s authors to flip two of Tiljander03′s correlations around… those are pretty extreme changes in interpretations. Also note that Kaufman09 (Science) corrected his MS to return the relevant proxies’ orientations to those proposed by Tiljander03, when he was made aware of the issue by McIntyre. Mann09 (Science) did not. So we have the spectacle of three recent and near-contemporaneous papers: one revised to be concordant with the relevant authority, and two that are discordant. Can a given value in a lakebed varve–say, an increase in Lightsum over time–mean Cooling (Tiljander03, Kaufman09) and, also, mean Warming (Mann08, Mann09)? How would that work, exactly?<br />
<br />
> 1. That a substantial part of his paper’s new results depend on one set of geographically isolated samples…<br />
> 2. That CPS doesn’t work.<br />
<br />
I’m uneasy about the methods, but on an intuitive level. FWIW, it seems to me that worthwhile commentary has been written by Steve McI & RomanM (CA), and Jeff Id (the Air Vent); check those sources.<br />
<br />
> 3. And that the samples passed correlation screening…<br />
<br />
The 1926 paper that Spence_UK links to provides an answer to those questions.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237625">AMac78 -- Aug 3, 2010 at 3:59 PM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237602" rel="nofollow">scientist (Aug 3 14:49)</a> (Further comments to follow #237614),<br />
<br />
> Mann seems to have had an overly simple conception of the Tiljander series (bigger number=thicker layer=warmer year).<br />
<br />
Not really. The authors accessed the four data series, considered the cautions in Tiljander03 and decided they weren’t crucial, then performed their screening and validation tests as described in the SI. The resulting r values are presumably as described –<br />
<br />
0.3066 Darksum<br />
0.2714 Lightsum<br />
0.2987 Thickness<br />
0.1232 X-Ray Density<br />
<br />
All are relationships between {proxy quantity} and {temperature} are positive. The issue is that this calibration is to the non-climate-related signals that progressively affected the lakebed sediments in the post-1720 period, according to Tiljander03.<br />
<br />
> [Mann & coauthors] likely used theses series without enough understanding of their limitations.<br />
<br />
Yes.<br />
<br />
> So he… should have informed the readers than his chronology was dependant on a new geo-isolated set of proxies…<br />
<br />
If Mann08′s authors were aware of their redefinition of the relationships of {proxy values} to {temperature}, then yes, they should have done so. But since they were likely unaware of the problem, how could they have done so?<br />
<br />
> I would be interested if he thinks the varve series are “good”, “debatable”…, or completely unsuitable.<br />
<br />
Prof. Mann has declined opportunities to address this issue.<br />
<br />
> not impressed with the Tiljander work in terms of a decisive explanation of the sediments. She does not construct a temperature series.<br />
<br />
Can you suggest how she was to construct a pre-1720 temperature series, for the portion of the varve record that was least affected by non-climate local signals?<br />
<br />
> I don’t understand… the issue of LS, DS and XRD and wonder if they are all independant…<br />
<br />
Good question. Lightsum is meant as a proxy of mineral content, Darksum as a proxy of organic content. XRD appears to be a digitization of X-Ray film’s grayscale density, once a core of defined thickness has been X-rayed. It’s unclear to me whether the Lake Korttajarvi record should be considered “one proxy” or “multiple proxies.” (But this is a second-order issue.) For more discussion (but no clear-cut answers) on physical data that can be extracted from lakebed cores, see the PDF linked at Jarmo’s comment, supra.<br />
<br />
> I’m concerned about the issue of compaction. How is this addressed?<br />
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I don’t believe it has been discussed in the context of Mann08; this seems like a distinctly second-order consideration. It is considered in the sedimentology literature (no citation).<br />
<br />
[snip]<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237633">scientist -- Aug 3, 2010 at 4:27 PM</a> <br />
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<span style="color: #660000;">1. When I said he should have disclosed the concerns, I didn’t mean that he knew it and failed to do so.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> 2. I don’t understand your comment, first you say that he was well aware of the limitations (in SI) and then you say, not.</span><br style="color: #660000;" /> <br style="color: #660000;" /><span style="color: #660000;"> [snip]</span><br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237639">amac78 -- Aug 3, 2010 at 5:10 PM</a><br />
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Re: scientist (Aug 3 16:27),<br />
<br />
> 1. When I said he should have disclosed the concerns, I didn’t mean that he knew it and failed to do so.<br />
<br />
Agreed.<br />
<br />
> 2. first you say that [Mann] was well aware of the limitations (in SI) and then you say, not.<br />
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Mann08′s authors were clearly <i>aware</i> of the issues, as they discussed them. They then went on to use the data. Either they <i>knew</i> they were bad (very unlikely, IMO), or they figured that the problems weren’t that severe after all (consistent with what they wrote in the SI). One flag they seem to have missed was that the calculated correlations for lightsum and XRD were inverted with respect to Tiljander03′s interpretations. <i>If they’d noticed these two “upside-down” interpretations</i>, they would have been obligated to describe them. Yes?<br />
<br />
[snip]<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237655">amac78 -- Aug 3, 2010 at 7:20 PM</a><br />
<br />
Re: <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237651" rel="nofollow">scientist (Aug 3 18:57)</a>, <br />
<br />
[snip]<br />
<br />
On the science, per MikeN, is “one or the other” wrong? <i>Stoat</i> blogger William Connolley didn’t think so. On this point, he said, “[Kaufman] is right and Mann is right.” (<a href="http://amac1.blogspot.com/2009/12/stoat-s-first-debate-on-use-of-lake.html" rel="nofollow">inline remark at Comment #16</a>).</span><br />
<span style="font-size: 85%;"><br />
Incidentally, Kaufman09′s authors used a splicing procedure so that they could <i>avoid</i> attempting to calibrate the Tiljander proxies to the post-1850 instrumental record. That is why they could decide to use the Tiljander03-concordant orientation for the proxies on an <i>a priori</i> basis.<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237716">amac78 -- Aug 4, 2010 at 8:52 AM</a><br />
<br />
On reflection, the exchanges with ‘scientist’ yesterday on this thread serve to illustrate the bind that the authors of Mann08 have placed themselves in.</span><br />
<span style="font-size: 85%;"><br />
It’s highly likely that Tiljander03′s overall interpretations of the Lake Korttajarvi data series as climate proxies pre-1720 are generally correct. [Note: since writing this comment, 'scientist's' observations have made me doubt the value of any of the four data series at issue as temperature proxies in the pre-1720 period -- AMac]<br />
<br />
Tiljander and her advisor and co-authors are the sole ‘local’ authorities; their views are consistent with other paleolimnologists’. E.g. McIntyre’s cite of Atte Korhola, supra (#237675), Antti Ojala’s citations of Tiljander and Saarinen in his 2001 dissertation (linked by Jarmo #237548), Tomi Luoto’s repeated citations of Tiljander03 in his 2010 dissertation (linked by Jarkko #237696), Ianl8888′s remarks supra.<br />
<br />
There are no qualified experts that have expressed contrary views, to my knowledge.<br />
<br />
<b>The first part of Mann08′s authors’ self-inflicted bind</b><br />
<br />
If Tiljander and coworkers are correct: Mann08′s authors are wrong.<br />
<br />
First, they are wrong because they ignored Tiljander03′s (and Tiljander05′s) warning that the Lake Korttajarvi data series would not be calibratable to a post-1720 climate record. Mann et al. thus calculated four nonsense correlations (Yule, 1926), one for each proxy, and proceeded with their paleotemperature reconstructions.<br />
<br />
Second, they are trivially wrong because in calculating their nonsense correlations, they failed to notice that they had turned two of Tiljander’s data series upside-down, Lightsum and XRD.<br />
<br />
Third, Mann and co-authors have undertaken a substantial violation of scientific ethics (viz: “Cargo Cult Science”) by failing to acknowledge and correct their mistakes, in their February 2009 PNAS Response to McIntyre and McKitrick, and again (implicitly) when uploading their first re-do of SF8a on their PSU website in late 2009, and again (implicitly) when uploading their second re-do of SF8a on their PSU website in early November 2009.<br />
<br />
In addition, it seems fair to suggest that other climate scientists who knew better, or should have known better, have worked to enable Mann08′s authors, helping them to dig in deeper rather than searching for a way out.<br />
<br />
<b>The second part of Mann08′s authors’ self-inflicted bind</b><br />
<br />
If Tiljander and coworkers are wrong: Mann08′s authors are wrong.<br />
<br />
“Tiljander and coworkers wrong” must mean two things.<br />
<br />
First, that their warning about post-1720 non-climate contamination of the varve record did <i>not</i> render their data series unusable in the 19th and 20th centuries, and thus related to the instrumental temperature record only by nonsense correlations.<br />
<br />
Second, that Tiljander03′s pre-1720 assignment of the relationship of data series to temperature was <b>correct for Darksum</b>, but <b>flat-out wrong for Lightsum</b> and <b>flat-out wrong for X-Ray Density</b>. “Flat-out wrong” in these two cases means “upside-down”: Tiljander03 asserts that rising proxy values correlate to <i>cooling</i> temperature, while Mann08 claims that rising proxy values correlate to <i>warming</i> temperatures.<br />
<br />
To my knowledge, there is no reason to think that this is the pathway that Mann08′s authors took to accomplish their paleotemperature reconstructions. <b>But this is the line of reasoning that</b> [some of]<b> Mann08′s enablers <strike>consistently</strike> refer to.</b> It is implicit in the “I don’t know, and it doesn’t matter” defense that has been proffered in Gavin Schmidt’s post at Collide-a-scape and by Martin Vermeers and others at Arthur Smith’s “Michael Mann’s errors” post.<br />
<br />
So let’s explore it further.<br />
<br />
<i>If</i> this is correct (again, I don’t think it plausible), then Mann08′s authors have engaged in a substantial breach of scientific ethics (viz: “Cargo Cult Science”) by citing and quoting Tiljander03 as an authority on the Lake Korttajarvi data series, while failing to note that their paper was departing completely from the cited interpretations. This would be highly misleading to PNAS’ editors, to peer reviewers, and to readers.<br />
<br />
Secondly, one would have to ask about this part of Mann08′s bind: <b>“What are the odds?”</b> <br />
<br />
While apparently knowing nothing about Finnish varved lakebed sediments, Mann08′s authors defy the sole authority’s warning on contamination.<br />
<br />
In constructing their proxies for paleotemperature, these authors then accept the sole authority’s orientation (but not correlation) on Darksum, reject their orientation (and thus correlation) on Lightsum, reject their orientation (and thus correlation) on XRD, and invent a new correlation on Thickness.<br />
<br />
And this process yields a skillful and validated reconstruction! Heck: Gavin Schmidt says that these proxies even <i>extend</i> the validation of the essential no-treering EIV reconstruction from 350 years to 850 years!<br />
<br />
<b>Wow! Talk About Lucky!</b><br />
<br />
- - - - - - - - - -<br />
<br />
That's the end of Part 1 of this exchange. The remainder can be found as <a href="http://amac1.blogspot.com/2010/08/part-2-synopsis-of-some-tiljander.html">Part 2: Synopsis of some Tiljander-related arguments</a>.<br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com1tag:blogger.com,1999:blog-7805174.post-21566124265373342642010-08-07T10:16:00.000-07:002010-08-11T12:57:40.692-07:00MikeN weighs in on Mann08's use of the Tiljander proxies<span style="font-size: 85%;">One thing that I <i>can't</i> do is evaluate the MatLab code that Prof. Mann placed online when <i>PNAS</i> published Mann08 in September, 2008. I can't even make heads or tails of Steve McIntyre's "R"-based emulations of Mann08... when it comes to running even simple programs, I'm an illiterate (gasp!).<br />
<br />
MikeN is a frequent participant at technical <i>Climate Audit</i> discussions. The latest has been <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/">The No-Dendro Illusion</a>. He has offered considerable insight within the threads at Arthur Smith's posts at <i>Not Spaghetti</i> considering the use of the Tiljander proxies in the Mann research group's recent efforts: <a href=":http://arthur.shumwaysmith.com/life/content/wheres_the_fraud">Where's the fraud?</a>, <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors">Michael Mann's errors</a>, and <a href="http://arthur.shumwaysmith.com/life/content/open_thread">Open Thread</a>.<br />
<br />
Via email, he offered a summary of his views of Mann08's use of the Tiljander proxies. With minor edits, his remarks follow.<br />
</span><br />
<a name='more'></a><span style="font-size: 85%;">AMac --<br />
<br />
It's important to understand how Mann08's code handles the data series used in multiproxy paleotemperature reconstructions. I have taken the path of working things through at Arthur Smith's bit by bit [see the three posts referenced above]. It might be useful to have a summary up on your site for future reference.<br />
<br />
To this point:<br />
<br />
My remarks are, in part, a response to your summary at <i>Climate Audit</i> [<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237716">Comment #237716</a>]. <br />
<br />
First, the authors did not flip Tiljander's proxy, they <i>failed to flip</i> the proxy. Similarly, the correlation or calibration steps did not flip the proxy.<br />
<br />
Here is my analysis of the code, which was seconded by Martin Vermeer [in the <i>Not Spaghetti</i> comments]. This was for Mann et al (2008), applying the CPS approach (the EIV approach is distinct).<br />
<br />
First, a data file is read with the various proxies, their latitude and longitude, etc. Each data file includes a class datapoint. In the case of Tiljander, that class is "4000".<br />
<br />
After being read in, the code is processed by checking each 5 degree by 5 degree gridcell in sequence, to see which proxies' latitudes and longitudes belong to that particular gridcell. McIntyre has noted previously that this procedure will double count proxies that are located on a gridcell boundary (and could potentially quaduple-count proxies on a corner). In this same early stage, each proxy passes through an "if" statement, where the correlation is checked to see whether it is higher than a predefined value. This is specified as either 0.106 or 0.128. <br />
<br />
What's being considered here is the correlation of the candidate proxy data with the 5 x 5 gridcell's temperatures 1850-1995, as calculated by CRUTEM3v from the instrumental record. <br />
<br />
So if a class 4000 proxy candidate has a negative correlation to its gridcell's CRUTEM3v temperature series, then this candidate will fail screening, and will not be used. (Correlations to neighboring gridcells' temperature series can also be checked.) The code will <i>not</i> flip this type of data series.<br />
<br />
All four of the Tiljander data series increase over time, from 1850 to 1995. This is true for Darksum, Lightsum, X-Ray Density, and Thickness. Since CRUTEM3v also increases over this time for this gridcell, the correlations are all positive.<br />
<br />
Controversy has arisen because Tiljander03 assigns "warmer" to <i>falling</i> values of Lightsum and XRD--opposite ("upside-down") from the trend that is observed in recent times. Mann08's critics claim that the <i>positive</i> correlations for {Lightsum vs. Temperature} and {XRD vs. Temperature} are spurious, since the increasing values of these measures through modern time is the result of non-climate-related factors.<br />
<br />
Be that as it may: these data series are fed in without flipping, the correlations are positive, and candidates are accepted if the r-values are above the cutoff (this is the case for Lightsum, but not for XRD).<br />
<br />
What I see is that there is no chance of one of the Tiljander proxies being flipped by the MatLab code, whether or not "human eyes" would consider it to be "upside down" on physical grounds. For class 4000, regression screening is not "blind to the proxy's sign." This class is processed with a one-sided test. <br />
<br />
Perhaps some confusion has stemmed from the different treatment by the MatLab code of different classes of proxies. In particular, there is a section that contains this code:<br />
<blockquote>if(abs(z(ia,i))>corra) ... and then z(i)*sign(z(ia,i))</blockquote>When a proxy with a negative correlation is processed by this step, it will be flipped. <br />
<br />
However, this isn't relevant for any of the four Tiljander data series, since they are all assigned to class 4000. Recall that at an earlier stage, the correlation had to be higher than 0.106 or 0.128 to pass. Thus, at this stage, all successfully-screened class 4000 proxies would pass through this section of code without risk of being flipped.<br />
<br />
-- MikeN</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com5tag:blogger.com,1999:blog-7805174.post-31066149713344543972010-08-05T21:06:00.000-07:002010-08-11T12:57:59.528-07:00Two views of Tiljander<span style="font-size: 85%;">On Aug. 4 at <i>Collide-a-scape</i>, Keith Kloor presented an e-mail interview of Gavin Schmidt, the NASA climate modeler and <a href="http://www.realclimate.org/">RealClimate.org</a> blogger, <a href="http://www.collide-a-scape.com/2010/08/04/gavins-perspective/">Gavin's Perspective</a>. It's a generally interesting read. After the post went up, Gavin stayed around to field accodades and brickbats from readers. After some questions about the Tiljander/Mann Affair went unanswered, I penned a Tiljander For Beginners essay at #127, and invited Gavin's thoughts. He duly responded with his view at #188.<br />
<br />
The two perspective pieces are side-by-side, below.<br />
</span><br />
<a name='more'></a><span style="font-size: 85%;"></span><br />
<table align="center" border="2" cellpadding="10" cellspacing="1"><tbody>
<tr><th>AMac's view<br />
<a href="http://www.collide-a-scape.com/2010/08/04/gavins-perspective/comment-page-4/#comment-13038">Comment #127</a></th> <th>Gavin's view<br />
<a href="http://www.collide-a-scape.com/2010/08/04/gavins-perspective/comment-page-4/#comment-13149">Comment #188</a></th></tr>
<tr><td valign="top" width="50%"><span style="font-size: 85%;">Certain aspects of the Tiljander story are straightforward, and easy for educated laypeople to grasp.<br />
<br />
(1) The paleotemperature reconstruction strategy employed by Prof. Mann’s research group in their 2008 <i>PNAS</i> paper (”Mann08″) <i>absolutely required</i> that each data series (”proxy”) be calibrated to the instrumental temperature record that spans 1850 to 1995.<br />
<br />
(2) Mann08’s authors considered using the many-thousand-year record of lake-bed sediments that graduate student Mia Tiljander and her advisor collected and analyzed from the bottom of Lake Korttajarvi in Finland. In their paper (”Tiljander03″), Prof. Matti Saarnisto and his student warned that their lakebed data became progressively more unreliable from ~1720 on, as the sediments recorded nearby activites unrelated to climate: farming, peat cutting, roadbuilding, bridge reconstruction, and lake eutrophication.<br />
<br />
(3) Mann08’s text acknowledges these issues as potential problems. However, the paper’s authors went ahead and incorporated four data sets from Tiljander’s work into their own reconstruction.<br />
<br />
(4) The post-1720 contamination of the Lake Korttajarvi data series turns out to be much, much worse than Mann08’s authors suspected. Anyone who looks can quickly grasp the problem. <a href="http://cdn.bitbucket.org/amac/tiljander-proxy-graphs/downloads/TiljProxies.jpg">This JPEG</a> [copied below] is a graph of three of Tiljander’s series: “Darksum,” “Lightsum,” and “X-Ray Density” (in each case, Tiljander03’s “warmer” is plotted “up.”) It shows 2,000 years’ worth of data, using a running 20-year average to smooth out the curves. Look to the 1850-1995 interval at the right of the picture, where the instrumental temperature record is available for proxy calibration. Yikes!<br />
<br />
(5) Mann08’s authors found a strong correlation between the rising temperature in southern Finland, 1850-1995 and the rising value of “Darksum” (r=0.3066). They got another one between rising temperature and rising “Lightsum” (r=0.2714). These are “spurious correlations,” unrelated to any pre-1850 climate signals that are contained in the sediments.<br />
<br />
(6) In and of itself, this error is not a big deal. Scientists make mistakes all the time. The controversy has arisen over the refusal of Prof. Mann and his co-authors to acknowlege what happened, straighten out the mess, and incorporate any lessons into best scientific practices.<br />
<br />
Judy Curry has written extensively about the woeful effects of Tribalism on Climate Science. The Tiljander/Mann affair is an object lesson of its dangers. Each reader will have their own take–and many partisans will bring their own spin to the analysis. In this Comment, I’ve sketched my own view of the matter. Perhaps, with Prof. Curry’s insights in mind, it will be possible to find more constructive ways of handling this (and future) controversies that arise at the interface between professional climatologists and citizen-scientists. </span></td> <td valign="top" width="50%"><span style="font-size: 85%;">For the sake of completeness, I will simply repeat what I have said before on various [<i>RealClimate</i>] threads, This is drawn entirely from the Mann et al (2008, 2009) papers (so you could just cut out the middle man). I’m not sure why people think that asking the same question a dozen times in different places will get a different answer, but here goes…<br />
<br />
1) Varved lake sediments often contain climate related signals, through changes in temperature, local runoff, stratification. Tiljander et al (2003) reported on records taken from a lake in Finland. They also reported possible anthropogenic contamination of their signal in more recent centuries. This makes them potentially useful, but also potentially dubious.<br />
<br />
2) Mann et al (2008) used these proxies (4 out of 1209) as input data into two reconstruction methodologies. One (CPS) requires a local correlation to temperature before they can be used, the other (EIV) does not. In CPS, the local correlation requirement fixes the orientation of any proxy – if you have an a priori expectation that it should be a different way, that proxy cannot be used.<br />
<br />
3) Since Mann et al (2008) were very aware of the potentially dubious nature of the modern portion of the Tiljander proxies, they performed their reconstructions without those proxies (and three others with potential problems) in sensitivity tests in the supplemental information (specifically Fig S8). Neither reconstruction (for NH mean (EIV) or NH land (CPS) temperature) is materially affected by the absence of the Tiljander proxies. This is the identical result to what you would have if you had a priori insisted on the opposite orientation of the proxies in CPS.<br />
<br />
3) The reconstruction without the Tiljander proxies validates back to 700 AD (NH mean, EIV) or 400 AD (NH land, CPS).<br />
<br />
4) If you think the Tiljander proxies are not usable or must be used in a different orientation, then Mann et al (2008) already showed what difference that makes to the overall reconstruction. There is nothing else left to do. All code and all data are available online for people to check this for themselves.<br />
<br />
5) Please read the papers. Nothing stated in the RC posts or comments was incorrect. There is a sensitivity to how far back you can go without tree rings if you drop the Tiljander proxies as well. So if you don’t like them, and are convinced that tree rings are useless, these methodologies don’t allow you to say anything before 1500 (compared to 1760 in the original MBH) (though the structure is <a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxyMeans07/NHcps_no7_v_orig_Nov2009.pdf">pretty similar</a> back further (CPS)) (see SI in Mann et al 2009 for the EIV result). Other methodologies may still be useful (cf Osborn and Briffa, 2006; Moberg et al, 2004). If however, you think that tree rings do contain useful climate information (see Salzer et al, 2009 for instance), then you get validated reconstructions back to well before medieval times. All validated reconstructions show late 20th Century warmth as anomalous over the their range of validity.<br />
<br />
(Consequences of all this)/(amount of time devoted to discussing it in the blogosphere) = a very small number.</span></td></tr>
</tbody></table><br />
<span style="font-size: 85%;">Here's the picture of the three Tiljander data series that's linked within my piece. Darksum, Lightsum, and X-Ray Density are all oriented such that "up" represents "warmer," according to the interpretation specified in Tiljander03. To show them as they are employed in Mann08 (see that paper's Fig. S9), the images of Lightsum and X-Ray Density would need to be flipped so that high data values are near the top (Tiljander03 and Mann08 agree on the orientation of Darksum, as shown). The grey shaded area to the right covers the data on sediments that were deposited after 1720, about the time when Tiljander03 states that non-climate contamination began its growth. The very steep increase in non-climate signals through the 19th and 20th Centuries is strikingly obvious for Darksum and Lightsum.<br />
<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjNHool8n4fnNV17qhJ-oCKBD1LHbXlosePQLx3aUGqOrO4yeV9cljqnInVQYArbVfrYRJOL29knwdhdyIjQh1NVIxOOOKYJrtL1qC-W-It1OdRKP_1AQxzovK-o3cQ8f0k88MGg/s1600/TiljProxies.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjNHool8n4fnNV17qhJ-oCKBD1LHbXlosePQLx3aUGqOrO4yeV9cljqnInVQYArbVfrYRJOL29knwdhdyIjQh1NVIxOOOKYJrtL1qC-W-It1OdRKP_1AQxzovK-o3cQ8f0k88MGg/s640/TiljProxies.jpg" width="425" /></a></div><br />
In the thread following the Collide-a-scape post <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/">The Main Hindrance to Dialog (and Detente)</a>”, <a href="http://rankexploits.com/musings/">Lucia</a> memorably noted Gavin’s pronounced tendency to answer questions regarding the uses of the Tiljander proxies… but to <i>not</i> answer the questions that were actually being asked. <br />
<br />
In that light, here are the six points I made, and my view of the response contained in Gavin's answer.<br />
<br />
(1) Mann08′s methods require direct calibation of all proxies to the 1850-1995 temperature record. <br />
* <i>Ignored.</i><br />
<br />
(2) Tiljander warned about post-1720 contamination in the Tiljander proxies. <br />
* <i>Somewhat addressed -- but "<b>potentially</b> dubious nature”?</i><br />
<br />
(3) Mann08 considered the warnings, then went ahead and used the proxies. <br />
* <i>Tacit agreement.</i><br />
<br />
(4) The 19th and 20th Century contamination was really bad, as a glance at a figure will show. <br />
* <i>Ignored.</i><br />
<br />
(5) The correlations that Mann08 thought they found between 1850-1995 temperature and proxy signals were actually spurious correlations to contaminating non-climate signals. <br />
* <i>Ignored.</i><br />
<br />
(6) The mistake itself isn’t such a big deal, refusing to fix the problem is the issue. <br />
* <i>Ignored.</i><br />
<br />
Which perspective hews closer to the truth, and has greater explanatory power? For many people, I imagine the answer will rather depend on their pre-existing views. Time will tell...</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com10tag:blogger.com,1999:blog-7805174.post-26136415303525002782010-08-04T04:56:00.000-07:002010-08-11T12:58:15.394-07:00Backgrounder on Analysis of Freshwater Lakebed Varved Sediment Cores<span style="font-size: 85%;">Deep in the thread following the <i>Climate Audit</i> post <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/">The No-Dendro Illusion</a>, "Ianl8888" made a series of remarks that provide valuable context to the 2003 <i>Boreas</i> paper by Mia Tiljander et al.<br />
<br />
His (or her) remarks follow, with minor edits for style.<br />
</span><br />
<a name='more'></a><span style="font-size: 85%;"><a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237687">Aug 3, 2010 at 11:59 PM</a><br />
<blockquote>“Compression” (i.e. lithification) is not a real issue [in the Tiljander03 analysis], as it does not change the parameters of the initial deposition except for water content. In fact, lithification makes the core sample easier to retrieve, and considerably lessens core loss. Such loss makes interpretation of the depositional environment more problematic. <br />
<br />
I have analysed the geophysical logs presented in Tiljander’s papers and agree with her estimates of minor core losses.<br />
<br />
One of the limiting factors in Tiljander’s thesis is the small area represented by the drillhole locations. This is essentially because the accessible fringe lake area itself is limited. The reason for wishing for wider geographical spread of sample points is that micro-disturbances (e.g. from sudden but small surges of water released by an ice break) can be more easily distinguished from broader conditions around the lake edge.<br />
<br />
If the bio-organism layers are identified as [deriving from] from warmer-weather species (as Tiljander et al. do), then bio-organism versus silicate thicknesses are seen as reliable proxies of warmer/colder conditions, in my opinion.<br />
<br />
[Mann08 employs four data series from Tiljander et al.'s analysis of the Lake Korttajarvi sediment cores: varve thickness, Darksum, Lightsum, and X-Ray Density. The question of the extent to which these measures are genuinely independent from one another has been raised earlier in the "The No-Dendro Illusion" comment thread.] I cannot see a four-factor situation here, just thicknesses, organic/silicate layer contents, and degree of sedimentation disturbance. But: human activity on the lake edges (especially driven piles for bridges) do most certainly interfere with the slow, delicate process of sedimentation, to the point of local destruction.</blockquote><a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237695">Aug 4, 2010 at 3:56 AM</a><br />
<blockquote>[Six points of clarification:]<br />
<br />
1) XRD analysis is to determine both the mineralogical composition and the ratio of inorganic/organic material in a sample. Compression and density have no bearing on this, nor does magnetic susceptibility.<br />
<br />
2) Varves are generally regarded as an accumulation of annual “pairs” of strata, crudely summer and winter.<br />
<br />
3) In summer [sic -- "spring"? - AMac], when water flows from melting ice are relatively more abundant and turbulent, sand/silt is deposited along with any debris from dying organisms (light-coloured stratum). In winter, clay particles are very, very slowly deposited (because these are so fine), generally with relatively little or no organic debris (dark coloured stratum). This deposition requires very undisturbed water to avoid re-stirring the particles, [which would keep them in suspension,] thus preventing deposition.<br />
<br />
4) Because the deposition process is so delicate in both seasons, anything that interrupts the water/sediment flows or equilibrium in any one year will result in a deformation of the annual “pair”. If the interruptions are long-lived (farming, bridge building, ditch-digging), the deformation [will likely result] in damaged strata succession over a considerable period (perhaps many years), making correlation with samples in other local geographical locations highly problematic.<br />
<br />
5) Tiljander’s papers may not be absolutely complete, but she knew which way is up (in the physical, strata succession sense), and also that persistent human interference around the lake edges inserted the likelihood of damaged varve succession, [and changes in sediment thickness and composition that are unrelated to the area's climate.]<br />
<br />
6) Altogether, [these data series derived from Lake Korttajarvi's varved sediments are] not a good temperature proxy.</blockquote></span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com4tag:blogger.com,1999:blog-7805174.post-77978884060548482672010-07-25T20:49:00.000-07:002010-07-28T19:53:34.737-07:00A Savings Account at the Paleo National Bank<span style="font-size: 85%;">Thanks to my town's Open Meeting Law, I'm able to follow local officials' actions pretty closely. Our Treasurer recently reported that, a few months ago, she switched the town's savings account to the Paleo National Bank. She was attracted by its generous offer of a 6% annual percentage rate. The latest Treasurer's Report included a summary of last month's savings account statement from the PNB. It looked like this: <br />
<blockquote>Beginning-of-month balance: $2,500.00<br />
Deposits: $200.00<br />
Withdrawals: $250.00<br />
Average Daily Balance: $1,841.54<br />
Interest: $6.20<br />
End-of-month balance: <b>$2,443.80</b>.</blockquote>At first, this looked okay -- but on closer inspection, the arithmetic seemed questionable:<br />
<blockquote>$2,500.00 + $200.00 - $250.00 <span style="color: blue;">+ $6.20</span> = <b>$2,456.20</b></blockquote>There's a difference of $12.40. It seems that Interest of $6.20 had been <i>debited from</i> rather than <i>credited to</i> the balance:<br />
<blockquote>$2,500.00 + $200.00 - $250.00 <span style="color: #cc0000;">- $6.20</span> = <b>$2,443.80</b></blockquote></span><br />
<a name='more'></a><span style="font-size: 85%;"><br />
And wait: the statement says the 6% Interest was calculated on an Average Daily Balance of $1,841.54 -- But the balance <i>couldn't</i> have dropped below $2,250.00, during the month.<br />
<br />
If the ADB had actually been about $2,400, the month's interest would have been about $12.00:<br />
<blockquote>$2,400 * 6%/yr * (1 year/12 months) = $12</blockquote>So the correct End-of-Month Balance should have been about:<br />
<blockquote>$2,500.00 + $200.00 - $250.00 <span style="color: blue;">+ $12.00</span> = <b>$2,462.00</b></blockquote>The End-of-Month Balance as calculated by the PNB seems to be about $18 too low.<br />
<br />
I asked the town's Treasurer about this, but she shrugged. Busy woman; she authorized me to talk to the bank if I wanted. When I phoned, the PNB representative didn't dispute my arithmetic... but he said that the bank had correctly calculated the balance. He repeated this point a number of times.<br />
<br />
So I drove to the local branch and met with Ekim, the manager. He reiterated that the PNB's calculations are most certainly correct. He went on to tell me that any claim to the contrary would be bizarre.<br />
<br />
I wasn't satisfied by these responses to my queries, so I wrote a Letter to the Editor, and sent it off to our local paper. Over the next few weeks, many senior employees of other banks wrote letters of their own. To my surprise, their accounts all supported Ekim's version, emphasizing that banks such as PNB had skillful senior executives, used rigorous accounting practices, and calculated their customers' balances with sophisticated computers. Many noted that Ekim had just won a "Top Manager" award. In a twist, a few executives darkly recalled the years of bad blood between retail bankers and stockbrokers, intimating that the reason I was raising this issue had to do with unspecified, hidden connections that I must have to the Stockbrokers' Association.<br />
<br />
But -- puzzlingly -- none of these bankers would go on the record to explicitly state,<br />
<blockquote>"The correct Interest was $6.20, and it was proper to debit Interest from the town account's balance."</blockquote>Instead, their contention on how the month's Interest should have been handled boiled down to,<br />
<blockquote>"I don't know, and it doesn't matter."</blockquote>The arithmetic underlying this controversy is straightforward and thus uninteresting. And the apparent $18 error is indeed rather small, and may not matter, as such.<br />
<br />
And yet: Ekim and his supporters in the banking industry have taken a position that seems tough to defend. They are justifying the PNB's handling of the town's account, but without offering any answers to the specific points that have been raised.<br />
<br />
What are we to think about how the PNB and similar banks go about their <i>other</i> business?<br />
<br />
- - - - - - - - - -<br />
<br />
<b>Remarks</b><br />
<br />
This post proposes the analogy of a simple and commonplace math problem -- calculating interest due on a savings account -- for the more esoteric dispute about the use of the Tiljander proxies in Mann08 (<a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html">references</a>, <a href="http://amac1.blogspot.com/2009/12/stoat-s-first-debate-on-use-of-lake.html">2009 discussion at <i>Stoat</i></a>, <a href="http://amac1.blogspot.com/2010/03/newly-discovered-jarvykortta-proxy-ii.html">'Jarvykortta River' walk-through of one Tiljander proxy</a>, <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/"><i>RealClimate.org</i>'s Gavin Schmidt defends Mann08 on this topic</a>). <br />
<br />
As with every metaphor, this one has weaknesses. Foremost, the tasks undertaken by scientists are ill-defined, challenging, and ever-changing -- in contrast to the focused, routine, and constant aspects of many of a branch manager's responsibilities. Professor Mann and his co-authors had to keep many balls in the air as they readied their 2008 <i>PNAS</i> paper for publication. It's not reasonable to expect perfection.<br />
<br />
But I think it <i>is</i> reasonable to expect the prompt acknowledgment and correction of clear-cut errors, once they are identified.<br />
<br />
In the story, there's a right way and a wrong to calculate 6% interest -- just as there are right and wrong ways to calibrate paleotemperature proxies to the instrumental temperature record. In both cases, the <i>sign</i> makes a difference, as well. Who ever heard of <i>subtracting</i> earned interest from a savings balance? In similar fashion: how could a proxy signal that communicates "warmer" be transformed into one that signifies "cooler," without an explanation?<br />
<br />
One could argue that the PNB's ~$18 error "doesn't matter." After all, it's only 0.7% of the town's final balance. On the other hand, customers assume that (1) the bank's procedures are correct, (2) the bank will follow those procedures, and (3) when mistakes are brought to its attention, they will be corrected. The PNB's attempt to close off discussion effectively disavows this approach.<br />
<br />
The support of other banks' employees might be heartwarming to branch manager Ekim, but most outsiders will understand that it is a discredit to the industry, and a public-relations blunder. If colleagues had persuaded Ekim to act according to the proper accounting standards, the issue would have been resolved with only minor embarrassment. By <i>supporting</i> his application of faulty arithmetic, they've encouraged him to "tough it out." Further, the bank executives' campaign will give the public the impression that faulty arithmetic is widely condoned within the banking industry. Unsupported allusions to the malign influence of anti-bank stockbrokers will further erode the reputation of the banking sector. Even if we stipulate that a cabal of brokers and their allies have engaged in much disreputable conduct over the years: <i>that's not the issue here.</i><br />
<br />
The application of arithmetic, logic, common sense, and widely-accepted procedures to a fairly straightforward problem: <i>that's</i> the issue.<br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com2tag:blogger.com,1999:blog-7805174.post-24729603485405550112010-07-12T17:10:00.000-07:002010-07-14T10:45:18.155-07:00Tiljander Proxies' Modest Effects on Mann08 Estimates... probably<span style="font-size: 85%;">Few things in life can be as rewarding as shouting "<b>I was wrong!</b>"<br />
<br />
<i>[Edit 7/13/10: That is, "probably wrong in thinking that the Tiljander proxies make an oversized contribution to Mann08's paleoclimate reconstructions (and still correct about other Tiljander-related issues)." Elaborated upon, below.]</i> <br />
<br />
One of the things that's annoyed Dr. Schmidt (see his <i>Collide-a-scape</i> 'guest post' <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/">The Main Hindrance to Dialogue (and Detente)</a>) and other AGW Consensus advocates has been my contention that the Tiljander proxies likely provide a substantial contribution to the "hockey stick" shape of the paleotemperature reconstructions in the Mann group's 2008 <i>PNAS</i> paper, "Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia" (see <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html">this post</a> for literature references). That stance has provided grist for the mill for protracted discussions at <i>Lucia's Blackboard</i> and other blogs. But...<br />
<a name='more'></a><br />
Last week, I started re-reading some of skeptical blogger Jeff Id's early posts, when he was first trying to sort out Mann08's methods and results. A figure from the 9/28/08 post <a href="http://noconsensus.wordpress.com/2008/09/28/mann-08-series-weight-per-year/">Mann 08 Series Weight Per Year</a> just about made me fall out of my chair. Here it is -<br />
</span><br />
<div class="separator" style="clear: both; text-align: center;"><span style="font-size: 85%;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVMIfh9ioMPCfEAez7XJWXFp00uRECRGFYfw3pXBEZKu_lpjWuB5lOmpNypab445en7vZuv4Pnt2BATmXzgf-CFqYwXyy1Wj6RiMr8YC7sTgWB7xUEK_ofmFVcywR1MuNxhMdMEw/s1600/JeffId-full-series1-080928.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="380" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVMIfh9ioMPCfEAez7XJWXFp00uRECRGFYfw3pXBEZKu_lpjWuB5lOmpNypab445en7vZuv4Pnt2BATmXzgf-CFqYwXyy1Wj6RiMr8YC7sTgWB7xUEK_ofmFVcywR1MuNxhMdMEw/s640/JeffId-full-series1-080928.jpg" width="640" /></a></span></div><span style="font-size: 85%;"><br />
There are some caveats surrounding the interpretation of this graph. Mainly, this is data from an emulation of Mann08's land-plus-ocean reconstruction by EIV that was accomplished by back-calculation, and doesn't produce a nearly-exact copy. See Jeff's post for details. <br />
<br />
But one point shines through: The Tiljander proxies are represented in gray, at the bottom of the graph (the legend reads "Sediment Finland").<br />
<br />
<i>Throughout the time series, they contribute less than 5% to the reconstruction</i>. Other proxies contribute the other 95%-plus portion of the signal. So if Jeff is right -- he probably is --<br />
<br />
<b>I was wrong</b>.<br />
<br />
<i>[Edit 7/13/10: That is to say, Jeff Id's estimate of the contributions of various proxies suggests only a modest contribution to this Mann08 paleotemperature reconstruction by the Tiljander proxies. Other proxies are much more important. The other points that have been raised about the TIljander proxies remain. These include their uncalibratability to the instrumental record, and thus their faux calibration by Mann08's authors. They also include the use of XRD and lightsum in an orientation that is inverted, with respect to the orientation proposed in Tiljander03. Do these other points still </i>matter<i>? Obviously, it depends on your definition of that word. I think the answer is clearly "yes," for a number of issues. One of them is outlined below.]</i><br />
<br />
I put versions of the following comment at Keith Kloor's <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/#comment-10611">Collide-a-scape</a>, Arthur Smith's <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors#comment-9706">Not Spaghetti</a>, and Lucia's <a href="http://rankexploits.com/musings/2010/encouraging-communication-or-purple-prose-award/#comment-48308">Blackboard</a>.</span><br />
<blockquote><div style="background-color: #cfe2f3;"><span style="font-size: 85%;">Here's some strong evidence in favor of the second part of the Gavin/toto answer to the Calibratability Question ("I don't know, and it doesn't matter.") To be clear, this argues <i>against</i> my assertion that "it does matter."<br />
<br />
Back in September 2008, blogger Jeff Id did some analysis of the proxies used in Mann08, and emulated some of Mann08's reconstructions, with much success. His post is <a href="http://noconsensus.wordpress.com/2008/09/28/mann-08-series-weight-per-year/">Mann 08 Series Weight Per Year</a><br />
<br />
Jeff estimates the contributions of various types of proxies at various points in time. His figure, "Percent Contribution to M08 Temp Reconstruction by Year" is worth examining in detail. It shows that in the earliest parts of the reconstruction he studied -- say, up through ~1100 or ~1300 -- the results are dominated by two types of proxies: cave precipitation records (yellow), and the Punta Laguna proxies (greenish-blue).<br />
<br />
The contribution of the Tiljander proxies (gray) is quite modest (well under 5%), throughout.</span></div></blockquote><span style="font-size: 85%;">Does this mean that the protracted controversy over the Tiljander proxies that started within days of Mann08's online publication has been a tempest in a teapot?<br />
<br />
I don't think so. There are a host of issues that remain. For instance, one point is raised in <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors#comment-9775">this comment</a> that I submitted to Arthur Smith's post "Michael Mann's errors" -<br />
</span><blockquote><div style="background-color: #cfe2f3;"><span style="font-size: 85%;">The "Tiljander" argument matters, even if Jeff Id's graph "Percent Contribution to M08 Temp Reconstruction by Year" and/or twice-revised Fig. S8a correctly represent the modest contribution of these proxies to the reconstruction.<br />
<br />
Comments in a recent post by IPCC AR5 WG2 author Ed Carr provide a timely illustration. The 9 July 2010 post at "Open the Echo Chamber" is <a href="http://www.edwardrcarr.com/opentheechochamber/?p=12">"Apparently, we have learned nothing..."</a> In the ensuing 50+ comment thread, some skeptics chime in with, well, skepticism about the IPCC process and the AR4 report. <a href="http://www.edwardrcarr.com/opentheechochamber/?p=12#comment-20">Here</a>, knowledgeable and articulate commenter 'caerbannog' reviews some reasons why criticisms of Prof. Mann's work by Steve McIntyre are ill-founded. He says,</span><br />
<blockquote><span style="font-size: 85%;">...you can generate hockey-stick-shaped leading principal components via [a non-centered PCA] method. But there’s an easy way to distinguish a “noise” hockey-stick scenario from one where the hockey-stick results from a real temperature signal.<br />
<br />
You look at the eigenvalue magnitudes...<br />
<br />
Any competent analyst trying to extract a temperature signal from proxy data via the PCA method would look at the eigenvalue magnitudes before deciding whether to proceed with the regression steps<br />
<br />
Had Mann’s eigenvalues looked like McIntyre’s noise eigenvalues, Mann would most likely said to himself, “There’s not much of a common temperature signal in my tree-ring data here; don’t think that I will be able to do much with it.”<br />
<br />
If Mann’s tree-ring eigenvalues had looked anything like McIntyre’s noise eigenvalues, Mann certainly would have realized that his tree-ring data did not contain any temperature information worthy of publication.<br />
<br />
This whole “spurious hockey-stick” argument used against Mann is completely without merit.</span></blockquote><span style="font-size: 85%;">Later in that conversation with 'Nullis in Verba', 'caerbannog' adds,</span><br />
<blockquote><span style="font-size: 85%;">Having a solid background in formal math/statistics is important, but it is also very important to be able to “relate” the numbers you’ve crunched with physical, real-world processes. That’s where many stats/mathematics types come up short — they haven’t worked with “real world” data enough to get practical experience with “real world” scenarios.<br />
<br />
And there’s no substitute for working with lots of “real world” data to get an appreciation for this.</span></blockquote><span style="font-size: 85%;">At the (current) tail of the comments [at Ed Carr's blog], I link to this post of Arthur's and <a href="http://www.edwardrcarr.com/opentheechochamber/?p=12#comment-54">remark</a>,</span><br />
<blockquote><span style="font-size: 85%;">...The use of proxies in the Mann group’s September 2008 article in PNAS (Mann08) sheds much light on [the use by Prof. Mann of screening, verification, and calibration steps in the evaluation and use of proxy datasets for paleotemperature reconstructions.] In particular, the Lake Korttajarvi varved lakebed sediments characterized by Tiljander et al (2003) are an important test case of this claim:<br />
<br />
<i>“Mann08 demonstrates methods of proxy selection and calibration for paleotemperature reconstruction that are robust.”</i><br />
<br />
In my opinion, analysis of Mann08′s use of the Tiljander proxies shows that this recent, high-profile paper clearly fails the “robustness” claim.</span></blockquote><span style="font-size: 85%;">The dialog between 'caerbannog' and 'Nullis in Verba' demonstrates that many people who are conversant with much of the technical detail of the controversies about the "Hockey Stick" are unaware of the issues associated with the selection and use of the Tiljander proxies. Being uninformed, they have not considered Tiljander's implications for the larger arguments they advance.</span></div></blockquote><span style="font-size: 85%;">I've got some ideas to follow up on, but they'll require that I become proficient in <a href="http://www.r-project.org/">R</a>. For me, that'll be a project with a long time horizon...<br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com7tag:blogger.com,1999:blog-7805174.post-43354079336759207572010-06-29T04:24:00.000-07:002010-07-14T10:45:18.156-07:00Ari Jokimäki Looks at the Tiljander Proxies<span style="font-size: 85%;"><strike>This post is a placeholder (29 June 2010). The immediate intent is to provide a link to two sites.</strike> <i>This post was written on 29 June 2010; corrections and minor additions made on 7 July 2010 are in italics. The objective is to provide some data and links to accompany recent posts by Ari Jokimäki and <a href="http://arthur.shumwaysmith.com/life/content/wheres_the_fraud">Arthur</a> <a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors">Smith</a>.</i> <br />
<br />
First, Ari Jokimäki's new analysis of the Tljander proxies, particularly XRD, <i>X-Ray Density</i>. His post at <i>AGW Observer</i> is <a href="http://agwobserver.wordpress.com/2010/06/28/tiljander/">Tiljander</a>.<br />
<br />
Second, here is a link to the Excel file <a href="https://bitbucket.org/amac/tiljander-proxy-graphs/downloads/Kort-gridbox-CRUtemv3.xls">Kort-gridbox-CRUtemv3.xls</a>, which contains monthly and annual <strike>CRUtemv3 </strike><i>CRUTEM3v</i> temperature anomaly records for the 5 degree by 5 degree gridbox that includes Lake Korttajarvi. It is downloadable from Bitbucket by clicking on the filename. <br />
</span><br />
<a name='more'></a><span style="font-size: 85%;"><br />
Note that the file contains two graphs of temperature anomaly vs. time for that gridcell. Here is the first: annual aveage temperature anomaly vs. time, along with the line generated by Excel's linear regression tool.<br />
<br />
</span><br />
<div class="separator" style="clear: both; text-align: center;"><span style="font-size: 85%;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYnf1MDw-4RyT6vOEtS-uSaQPDXNktMj5SoR01PsAHCBQYyRvqoDdBlMHyCy5NJliBlY3ABKlxOjm9qrfefu5EuygRgTIL9rwyb4sfdeJXGPuqoAK1zeBe371lInRVWEH2EEEcFw/s1600/Gridbox-temp.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="377" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYnf1MDw-4RyT6vOEtS-uSaQPDXNktMj5SoR01PsAHCBQYyRvqoDdBlMHyCy5NJliBlY3ABKlxOjm9qrfefu5EuygRgTIL9rwyb4sfdeJXGPuqoAK1zeBe371lInRVWEH2EEEcFw/s640/Gridbox-temp.jpg" width="640" /></a></span></div><span style="font-size: 85%;"><br />
The second graph adds the Tiljander X-Ray Density (XRD) proxy, using an 11-year rolling average. Note that the XRD proxy is plotted in its "upside-down" orientation. In other words, by the assignment of Tiljander et al. given in their 2003 <i>Boreas </i>article, "colder" is towards the top of the graph, while "warmer" is towards the bottom.<br />
<br />
However, climactic influences on the XRD proxy are of limited relevance with respect to these 19th and 20th Century values, according to Tiljander et al. The XRD record during this time is dominated by local non-climate-related contaminating factors. For details, refer to the <a href="http://amac1.blogspot.com/2010/03/newly-discovered-jarvykortta-proxy-ii.html">"Jarvykortta River" post</a>. <br />
<br />
</span><br />
<div class="separator" style="clear: both; text-align: center;"><span style="font-size: 85%;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGp61W4pgmITlKKuOF91Yc5ZIJqFpH8K8pZ7GYSWyTw6Or2UQ-PVaGSCNkJvGohdX5epKsHgA1nyvmTKoT76k2pSaSTx-WynMKi4F9iX9yQdEHh-hwdyn5HCQO2UqoyQbjexvD7Q/s1600/Gridbox-temp+XRD.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="417" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgGp61W4pgmITlKKuOF91Yc5ZIJqFpH8K8pZ7GYSWyTw6Or2UQ-PVaGSCNkJvGohdX5epKsHgA1nyvmTKoT76k2pSaSTx-WynMKi4F9iX9yQdEHh-hwdyn5HCQO2UqoyQbjexvD7Q/s640/Gridbox-temp+XRD.jpg" width="640" /></a></span></div><span style="font-size: 85%;"><br />
<i>The screening, validation, and calibration exercises in Mann08 relied on two instrumental surface-air temperature data sets for 1850-2006, maintained by the University of East Anglia's Climatic Research Unit instrumental surface-air temperature data from 1850 to 2006. CRU's records are archived at <a href="http://www.blogger.com/www.cru.uea.ac.uk/cru/data/temperature">this page</a>. "CRUTEM3v" estimates land temperature anomalies; "HadCRUT3v" estimates them for land and ocean combined. "v" refers to the adjustment by CRU of the anomaly values for variance.<br />
<br />
The 5-degree by 5-degree gridbox that includes the Lake Korttajarvi bore hole site encompasses 60N to 65N in latitude and 25E to 30E in longitude. I pulled the monthly temperature anomaly values for that gridcell from a download of the CRUTEM3v file, per instructions on the linked page. For each year, the values for months 1 to 12 were averaged to create an annual average. These yearly values are what are graphed above.<br />
<br />
Mann08 divided the 1850-1995 instrumental record into two calibration/validation intervals. Page 15253/4:<br />
</i></span><br />
<blockquote><span style="font-size: 85%;"><i>We evaluated the fidelity of reconstructions through validation experiments (see Methods), focusing here on NH land temperature reconstructions... The CPS and EIV methods... are both observed to yield reconstructions that, in general, agree with the withheld segment of the instrumental record within estimated uncertainties based on both the early (1850–1949) calibration/late (1950–1995) validation and late (1896–1995) calibration/early (1850–1895) validation.</i></span></blockquote><span style="font-size: 85%;"><i></i><br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com1tag:blogger.com,1999:blog-7805174.post-59093142890069241172010-03-10T21:37:00.000-08:002010-07-07T05:36:05.624-07:00The Newly-Discovered Jarvykortta Proxy -- II<span style="font-size: 85%;">This post is a rewrite of an essay I published on 28 Nov. 2009, <a href="http://amac1.blogspot.com/2009/11/newly-discovered-jarvykortta-proxy.html">The Newly-Discovered Jarvykortta Proxy: Relevant to the Tiljander Varve Series?</a> It's been edited and reformatted for clarity. I assume that a fictional monastery exists alongside a fictional "Jarvykortta River" (cf. the real Lake Korttajarvi) in fictional Ruritania (cf. Finland). The point is to explore whether a proxy series can be inadvertently used in an upside-down orientation. The example illustrates that Yes, such an error is quite possible. I argue that a data series refers back to one or more physical attributes. Care should be taken to see that such data are used in the orientation that makes logical sense, with respect to what they represent in the physical world.<br />
<a name='more'></a><br />
We begin.<br />
<br />
I recently returned from a trip to <a href="http://en.wikipedia.org/wiki/Ruritania">Ruritania</a>. While there, I met with the Abbott of the Jarvykortta Monastery, who told me that the monks have kept a continuous record of the ice breakup date of the adjacent Jarvykortta River since before 400 AD.<br />
<br />
Recalling the <a href="http://www.john-daly.com/nenana.htm">The Nenana, Alaska Ice Classic</a>, it struck me that the Monastery's record could be a useful data set for a multi-century paleotemperature reconstruction. Accordingly, I asked if I might have access to these records, and any other information the Abbott might have. He graciously agreed.<br />
<br />
Since recordkeeping began in the year 389, the date of the Jarvykortta River breakup has been as early as February 15 (in 1231) and as late as June 20 (in 1967). For graphing purposes, I have taken the 11-year rolling average of this series. In this, I followed the precedent set by Finnish graduate student Mia Tiljander, as far as how she handled the X-Ray Density data of the lakebed sediments that she analyzed from the bottom of Lake Korttajarvi, Finland. The reference to the Tiljander et al peer-reviewed publication from 2003 that describes that work is <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html">here</a>.<br />
<br />
(In fact, it was the Finnish <i>Lake Korttajarvi</i> XRD series and <b>not</b> this newly-discovered Ruritanian <i>Jarvykortta River</i> series that was used by Mike Mann's research group as one of the long-term temperature proxies in <a href="http://www.pnas.org/content/early/2008/09/02/0805721105">their 2008 peer-reviewed paper</a> in the journal PNAS.)<br />
<br />
Clearly, <i>temperature</i> could have an important influence on when the ice breaks up. Still, as with most proxies, there are some complications that must be considered. In that regard, the Abbott related the following three points to me:<br />
<ol><li>There is <u>a natural hot spring that empties into the Jarvykortta River</u>, about 1 kilometer upstream of the Monastery. Its flow is quite constant, year-to-year. This addition of hot water makes the river ice break up earlier than would otherwise be the case.<br />
</li>
<li>Around 1720, <u>local farmers began piping some of the hot spring's output</u> to their homes. As the population of the area grew in the 18th and 19th Centuries, this practice became more widespread. This reduction in hot-spring flow into the river likely led to increasing delays in the timing of the Spring breakup of the ice by the monastery.<br />
</li>
<li>For much of the 20th Century, <u>the nearby town maintained a skating rink for the winter and spring</u>, right in the river, just upstream of the monastery. Cooling coils were placed in the river to keep the ice solid, well into the spring. In the late 1920s/early 1930s, and again in 1967, hockey playoffs went into late May. Those years, the town kept the cooling coils going into the late Spring.<br />
</li>
</ol>The year-by-year record of the ice breakup, 389-1985, is graphed below.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzBhBqeG8-VG53p7t2ID7hS5ciUjnjd9gKcavGO11WVS97iyArFOHgMHB3tzn7tJaE17gwE2QPdKrLCcaKmwZ7e_sRXAF-Nok79U442IFTeuUkgMRuK0_s2-OmrfhUIamp5m1yAQ/s1600-h/Jarvykortta-yr-by-yr.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="196" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzBhBqeG8-VG53p7t2ID7hS5ciUjnjd9gKcavGO11WVS97iyArFOHgMHB3tzn7tJaE17gwE2QPdKrLCcaKmwZ7e_sRXAF-Nok79U442IFTeuUkgMRuK0_s2-OmrfhUIamp5m1yAQ/s400/Jarvykortta-yr-by-yr.jpg" width="400" /></a></div><br />
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Here is the same record, except smoothed by averaging adjacent years' dates. This is the output of an 11-year rolling average (as was shown by Tiljander et al. (2003) in their Figure 5, for the Lake Korttajarvi proxies).<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9TKbxj_pk9h-EOEchKWprg9Okc3iYpaMQPugc0YaFOObuDaXeryxqLI97uWJRnfLRuLQ0l316esnG3Y3nLyhbpasULXgoXWJ981DO0JRvlcowNYbFslhUeQP0dh4DNBLj89BoqQ/s1600-h/Jarvykortta-11yr-avg.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="197" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9TKbxj_pk9h-EOEchKWprg9Okc3iYpaMQPugc0YaFOObuDaXeryxqLI97uWJRnfLRuLQ0l316esnG3Y3nLyhbpasULXgoXWJ981DO0JRvlcowNYbFslhUeQP0dh4DNBLj89BoqQ/s400/Jarvykortta-11yr-avg.jpg" width="400" /></a></div><br />
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These data are downloadable <a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/">from BitBucket</a>, as the Excel file <a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/Jarvykortta-Ice-Out-Proxy.xls">Jarvykortta-Ice-Out-Proxy.xls</a>.<br />
<br />
So: how should the Ice-Out signal be connected to regional warming or cooling? The Abbott wisely suggested that when the winters are longer and harsher, the ice breakup is later in the year. Conversely, he offered, milder winters lead to an early breakup of the ice.<br />
<br />
The Abbott also counseled me to account for the confounding effects of the hot springs piping and the hockey rink on the date of ice breakup.<br />
<br />
As we parted, the Abbott offered me a warning on the pitfalls of over-reliance on computers. For instance, he noted, an algorithm might interpret the progressively advancing ice breakup date from 1850 to the present as the consequence of regional warming. That would lead to a very odd result, orienting the Jarvykortta River Ice-Out signal such that ice breakups <i>later</i> in the year would be correlated with <i>warmer</i> temperatures.<br />
<br />
"River ice breaking up in <i><b>June</b></i><b></b> as an indication of <i>mild</i> winters!," I exclaimed. "That makes no sense at all!"<br />
<br />
After saying my farewells, I set out on my trek back to the capital city. I stole a final look backwards towards the monastery, resplendent in the setting sun.<br />
<br />
The Abbott was chuckling.<br />
<br />
* * * * * * * * * *<br />
<br />
Leaving Ruritania and moving to Finland: during the course of her graduate studies at the University of Helsinki, Mia Tiljander had a leading role in obtaining cores of the silt at the bottom of Lake Korttajarvi. Because those sediments are "varved," they can be dated with precision to the year they were deposited. Tiljander and her advisor preserved the borehole cores and analyzed them, seeking information on the climate of the past 3,000 years in that part of Finland. These studies were written up in a 2003 peer-reviewed article in <i>Boreas</i>, and in her doctoral dissertation (references <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html">here</a>).<br />
<br />
Among her studies, Tiljander measured the ability of each year's deposits to absorb X-Rays. Low X-Ray Density (measured in greyscale values) indicates a high organic content of that year's sediment. The XRD values range from a low of 46 to a high of 172. Tiljander interprets a high organic content to mean that the summer was warm and the growing season long. <i>Boreas</i> (2003), page 570:<br />
<blockquote>The thickness of the organic lamina is the sum of autochthonous production within the lake and the amount of allochthonous material and is related to the primary production during the open water season. The layer above the mineral matter is defined as organic, because of the less dense structure in X-ray images and low grey-scale values. A thick organic lamina probably indicates a warm summer and a relatively long growing season.</blockquote>The allegorical Ruritanian "Jarvykortti River Monastery" proxy is comprised of a set of figures that is <i>identical</i> to the actual set of Lake Korttajarvi varve X-Ray Density greyscale values. Excel translated the numbers from greyscale values into days-of-the-year. <br />
<br />
For instance, the X-Ray Density of the varve that was deposited in 1220 was 54. So, in 1220, I had the ice on the Jarvykortta River break up on February 23--the 54th day of the year. In the decade of the 1220s, the ice broke up as early as Feb. 17 (1229), and as late as Feb. 28 (1225).<br />
<br />
By contrast, when 170 years had passed, the ice in front of the mythical Jarvykortti Monsastery broke up about 5 weeks later in the season. For the 1390s, the earliest year of the ice breakup was 1395 (March 20), while the latest was 1391 (April 15).<br />
<br />
In her paper's Table 2, Mia Tiljander noted 8 special periods of low X-Ray density (much organic matter; long growing seasons) and 10 special periods of high XRD (much mineral matter, short growing seasons). Among them:<br />
<br />
<table align="center" border="1" cellpadding="1" cellspacing="0"><tbody>
<tr><td> Years </td><td> Duration </td><td> Varve structures </td></tr>
<tr><td> AD 1380–1420 </td><td> 40 yr </td><td> Mineral matter </td></tr>
<tr><td> AD 980-1250 </td><td> 270 yr </td><td> Organic matter </td></tr>
</tbody></table><br />
Thus, according to Tiljander's interpretation, the low X-Ray Densities of the 1220s corresponded to a time of warmer summers and longer growing seasons. The higher XRD values of the 1390s indicated a time of cooler, shorter summers. <br />
<br />
These trends can be seen in the Lake Korttajarvi X-Ray density trace. Here it is, oriented in the same fashion as the days-of-the-year Korttajarvi River Monastery record, earlier. <br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsGXGnXIi6nObDa-BvBi82OA20sa2nj8fqWN3FKYZxL58-3yIVNpFLvN5w_uGjjoOy6ARlvzxU4NEZxg_8-HfpPoZczjyQthJmd1dd0aJLJ9Zi4FAXTZiJe8CJK0Vmpqw5Z26Hkg/s1600-h/Korttajarvi-XRD-upside-down.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="197" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsGXGnXIi6nObDa-BvBi82OA20sa2nj8fqWN3FKYZxL58-3yIVNpFLvN5w_uGjjoOy6ARlvzxU4NEZxg_8-HfpPoZczjyQthJmd1dd0aJLJ9Zi4FAXTZiJe8CJK0Vmpqw5Z26Hkg/s400/Korttajarvi-XRD-upside-down.jpg" width="400" /></a></div><br />
But it makes more sense to orient the Lake Korttajarvi varve record conventionally, such that <i>higher</i> temperatures are nearer the <i>top</i> of the graph.<br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUQqBv_X8WG-oxVaX9SDggdFntYXmxjVIdS012q0D7uIyg9ZZwX1UsnMIA4mfN4UbVL0j5MIGZXp_x4tFTANlXzBEwXwvrmlVBC4SD_uZLEMYQo72wAnU5mDXFSbJHaE9oSRo6GQ/s1600-h/Korttajarvi-XRD-rightside-up.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="196" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUQqBv_X8WG-oxVaX9SDggdFntYXmxjVIdS012q0D7uIyg9ZZwX1UsnMIA4mfN4UbVL0j5MIGZXp_x4tFTANlXzBEwXwvrmlVBC4SD_uZLEMYQo72wAnU5mDXFSbJHaE9oSRo6GQ/s400/Korttajarvi-XRD-rightside-up.jpg" width="400" /></a></div><br />
The grey-colored box to the right of the figure (1750-1995) serves as a reminder of Tiljander's warning that the Lake Korttajarvi record became progressively more dominated by local non-climate signals during the 18th, 19th, and 20th centuries. <i>Boreas</i>, page 572:<br />
<blockquote>In the case of Lake Korttajarvi it is a demanding task to calibrate the physical varve data we have collected against meteorological data, because human impacts have distorted the natural signal to varying extents during the past 280 years and the meteorological data in the Jyvaskyla area are only available since 1881.</blockquote>And <i>Boreas</i>, page 575:<br />
<blockquote>In the 20th century the Lake Korttajarvi record was strongly affected by human activities. The average varve thickness is 1.2 mm from AD 1900 to 1929, 1.9 mm from AD 1930 to 1962 and 3.5 mm from AD 1963 to 1985. There are two exceptionally thick clay-silt layers caused by man. The thick layer of AD 1930 resulted from peat ditching and forest clearance (information from a local farmer in 1999) and the thick layer of AD 1967 originated due to the rebuilding of the bridge in the vicinity of the lake's southern corner (information from the Finnish Road Administration). Varves since AD 1963 towards the present time thicken because of the higher water content in the top of the sediment column. However, the gradually increasing varve thickness during the whole 20th century probably originates from the accelerating agricultural use of the area around the lake.</blockquote>To recap, the mythical Jarvykortta Monastery records are unreliable from the mid-1700s on, thanks to hot-spring diversion and hockey rink operation. <i>The effect of both these artifacts was to progressively <u>increase</u> the date of ice breakup through the 19th and 20th Centuries -- a phony "getting cooler" signal</i>. <br />
<br />
In like manner, The Lake Korttajarvi X-Ray Density records are unreliable from the mid-1700s on, thanks to agricultural activities and road-building. <i>The effect of both these artifacts was to progressively <u>increase</u> varve X-Ray Density through the 19th and 20th Centuries -- a phony "getting cooler" signal</i>. <br />
<br />
In their search for suitable new temperature proxies, Mike Mann's lab group developed an algorithm that would identify records that showed statistically-significant changes during the 1850 to 1995 period of warming. The Lake Korttajarvi Varve record and the Jarvykorrta River Monastery record both show a pattern of rising X-Ray Densities or ice-out dates over that time. The rises coincide nicely with the computed Southeast Finland regional temperature trend. <br />
<br />
Rising Temperatures. <br />
Rising Values (XRDs or ice-out dates).<br />
<i><b>Match!</b></i><br />
<br />
<i>Is this statistically-significant linkage of the Lake Korttajarvi XRD record and the computed regional temperature trend reflective of a real-world connection?</i><br />
<br />
Even though the suggested relationship defies common sense?<br />
<br />
Even when contamination of the record has flipped the relationship Upside-Down from what it should be?<br />
<br />
* * * * * * * * * *<br />
<br />
Here's a comparison of the actual Lake Korttajarvi XRD proxy and the Ruritanian Jarvykortta River Monastery one:<br />
<br />
<table align="center" border="1" cellpadding="1" cellspacing="0"><tbody>
<tr><td><b>Series</b></td><td><b>Lake Korttajarvi Varve XRD</b></td><td><b>Jarvykortta River Ice Breakup</b></td></tr>
<tr><td>Characteristic</td><td>X-Ray Densities of Lakebed Sediments</td><td>Date of Ice Breakup of River</td></tr>
<tr><td>Source</td><td>Tiljander et al (2003)</td><td>Monastary Abbott</td></tr>
<tr><td>Dates</td><td>389-1985</td><td>389-1985</td></tr>
<tr><td>Low value</td><td>1231: 46 (greyscale)</td><td>1231: Feb 15 (46th day of year)</td></tr>
<tr><td>High value</td><td>1967: 172 (greyscale)</td><td>1967: Jun 20 (172nd day of year)</td></tr>
<tr><td>Influence of temperature on series?</td><td>Yes</td><td>Yes</td></tr>
<tr><td>Source’s interpretation of temp. effects</td><td>Harsher winters lead to mineral-rich varves and higher XRDs</td><td>Harsher winters lead to later date of ice breakup</td></tr>
<tr><td>Non-temperature natural influences on series?</td><td>Yes</td><td>Yes</td></tr>
<tr><td>Source’s interpretation of non-temp. influences</td><td>Higher precipitation increases XRD value</td><td>Lesser flow of hot springs upriver increases date of ice breakup</td></tr>
<tr><td>Human influences?</td><td>Yes</td><td>Yes</td></tr>
<tr><td>Source’s interpretation of human influences</td><td>1720 on, farming increased <br />
sedimentation and XRD values</td><td>1720 on, diversion of hot springs increased ice breakup dates</td></tr>
<tr><td>Known artifacts</td><td>Late 1920s: Peat cutting increased XRDs<br />
1967: Bridge reconstruction increased XRD</td><td>Late 1920s: Skating rink increased ice breakup date<br />
1967: Hockey final increased ice breakup date</td></tr>
<tr><td>Source’s summary</td><td>Higher XRDs mean lower temps, unreliable post-1720</td><td>Later ice breakups mean lower temps, unreliable post-1720</td></tr>
<tr><td>Mann et al (2008) <br />
interpretation</td><td>Computer screening algorithm <br />
1850-1995 shows that higher XRDs <br />
must mean higher temps</td><td>n/a</td></tr>
<tr><td>Common sense interpretation</td><td>Higher XRDs mean lower temps. Unreliable post-1720</td><td>Later ice breakups mean lower temps. Unreliable post-1720</td></tr>
</tbody></table><br />
* * * * * * * * * *<br />
<br />
It sounds plausible when defenders of the Upside-Down usage of the Lake Korttajarvi X-Ray Density proxy claim, "<i>The higher the varve XRD, the warmer the average temperature.</i>" After all, who goes through the day thinking about varve densities?<br />
<br />
But this is the same as claiming, "<i>The later in the season that river ice breaks up, the warmer the average temperature.</i>"<br />
<br />
Everybody knows that when the winter is warm, ice breaks up early--not late!<br />
<br />
The identical logic lets us know what Mia Tiljander's varve data is telling us about the climate in the vicinity of Lake Korttajarvi. For instance, it was warmer in the 1220s than it was in the 1390s.<br />
<br />
But the 1800s and 1900s? <i>Who knows?</i> <u>The record's no good.</u><br />
<br />
* * * * * * * * * *<br />
<br />
The controversy over the use of the Tiljander varve proxies is confusing, at first. <i>"Top-notch scientist Mann publishes in a prestige journal, skeptic McIntyre complains, Mann responds. AGW Consensus vs. Denialists, RealClimate.org versus ClimateAudit.org, bla bla bla. Who can tell?"</i><br />
<br />
But on closer inspection, it's simple story. The Mann group's calibration algorithm inadvertently flipped the X-Ray Density Tiljander proxy (and at least one other) so that Cold was interpreted as Warm, and vice versa.<br />
<br />
Whoops. Mike Mann made a mistake, Steve McIntyre was correct.<br />
<br />
In most other fields, this would have ended with Mann's group promptly acknowledging the error, re-doing the affected calculations, and submitting a formal Correction to the journal.<br />
<br />
It's going on two years, and there is no sign of that happening.<br />
<br />
Instead, a kaleidoscope of explanations, excuses, and Who's-On-First? routines has been set off by Mann's Delphic response in PNAS: that McIntyre's claim of an error was "bizarre." The spectacle continues to this day.<br />
<br />
I've read that: Mann was right--Proxies <i>can't</i> be upside-down--It's too complex for you to understand--Mann interpreted the proxies correctly, as did Tiljander and Kaufman too--There is no single "right" interpretation--The alleged mistake doesn't matter anyway--Look over there, a pony!--You have to be super-knowledgeable about varves to earn the right to an opinion--The proxy data are interpreted by <i>computers</i>, so orientation doesn't matter--Supplemental Figure S8a <i>proves</i> that Mann was correct--<i>Ah, grasshopper, what is this notion of "correct," anyway?</i>--<i>Lots</i> of other studies agree with the conclusions of Mann et al (2008)--Don't you have anything better to do with your life?--Mann's use of the proxies <i>is</i> consistent with Tiljander's interpretation--McIntyre's a fossil-fuel shill!--Mann should be free to ignore Tiljander's interpretation; maybe he did and maybe he didn't--Your simplistic attempts to negate the power of <i>statistical algorithms</i> don't fool anyone.<br />
<br />
And so on.<br />
<br />
But in science, this sound and fury signifies nothing. At the end of the day, the Mann lab's misplaced trust in their computational algorithms have fooled them into mixing up <i>colder</i> and <i>warmer</i>. It's as simple as that.<br />
<br />
Don't change the data to fit the theory--that's backwards!<br />
<br />
<i>[Update 12 Mar. 2010 -- minor text edits for clarity.]</i><br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com4tag:blogger.com,1999:blog-7805174.post-65062791998695581062010-03-06T12:31:00.000-08:002010-03-12T08:41:46.074-08:00Another Scientist Commends Mann et al. '08 -- Tiljander Notwithstanding<span style="font-size: 85%;">Last week, Roger Pielke Sr. headlined a critical email on his site, <a href="http://pielkeclimatesci.wordpress.com/2010/03/01/guest-post-by-chick-keller-on-the-content-and-tone-of-my-weblog/">Guest Post By Chick Keller On The Content and Tone Of My Weblog</a>. Dr. Keller is the retired Director of the Los Alamos National Laboratory Branch of the University of California’s Institute of Geophysics and Planetary Physics (IGPP). He's made significant contributions to the peer-reviewed literature on climate change (<a href="http://tinyurl.com/Chick-cv-pdf">PDF</a>).<br />
<br />
While I am not a regular reader of <a href="http://pielkeclimatesci.wordpress.com/">Pielke's blog</a>, such efforts to establish dialog among 'Consensus scientists,' 'skeptics,' and 'lukewarmers' are commendable. Given my own interests, I was most taken by the following paragraph from Chick Keller's post.</span><br />
<a name='more'></a><br />
<span style="font-size: 85%;"><blockquote>What about global and NH temperatures in the past 2,000 years? It’s just not good science to dismiss all this very careful work with — well I’m uncomfortable with the way they match proxy and instrumental data. Here a careful read of the National Academy of Sciences PNAS paper in 2008 (<a href="http://go2.wordpress.com/?id=725X1342&site=pielkeclimatesci.wordpress.com&url=http%3A%2F%2Fwww.pnas.org%2Fcontent%2Fearly%2F2008%2F09%2F02%2F0805721105.full.pdf">see Mann et al. 2008</a>) on the best work done to date on this is in order (as well as comparison with the several other different and mostly independent treatments of the subject by other authors–bore hole results, Moberg’s wavelet combination of low and high frequency proxies, Lonnie Thompson’s mountain glacier work, etc). Pretty hard to just dismiss out of hand all these people and their rather similar results.</blockquote>"<i>See Mann et al. 2008</i>" is a link to the PDF of the Mann group's high-profile paleoclimate paper in the high-impact, peer-reviewed journal <i>Proceedings of the National Academy of Sciences of the USA</i>. This is of course the work that sparked a controversy because of its use of the four lakebed sediment data series from Lake Korttajarvi, Finland -- the "Tiljander proxies."<br />
<br />
In the excerpted text, Chick Keller makes four claims about Mann et al (2008).<br />
<blockquote>1. Very careful work<br />
<br />
2. It's not good science to dismiss... the way they match proxy and instrumental data.<br />
<br />
3. Here a careful read of... the best work done to date on [temperatures of the past 2,000 years] is in order.<br />
<br />
4. Pretty hard to just dismiss out of hand all these people and their rather similar results.</blockquote>I don't agree. The treatment by the Mann group of the Lake Korttajarvi sediment proxies provides a good explanation of why. In <a href="http://www.centerforinquiry.net/forums/viewthread/7150/P15/#87224">this recent comment</a> at the Center for Inquiry Forum, I offered a precise formulation of this issue, and invited journalist Chris Mooney to ask Prof. Mann for his views (Mooney <a href="http://www.centerforinquiry.net/forums/viewthread/7175/#87471">declined</a> <i>[12 Mar. 10 link corrected]</i>). Here are those two questions, reprinted.<br />
<blockquote><b>Background</b><br />
<br />
In September 2008, Dr. Mann’s group published an important paper on Earth’s temperature history for the past 2,000 years in the prominent peer-reviewed journal <i>Proc. Natl. Acad. Sci. USA</i>. Temperature signals were extracted from many long-term data series, such as tree rings and ice cores. The paper has been strongly criticized for its inclusion of the lakebed sediments characterized by Finnish geologist Mia Tiljander. Critics claim that the four Tiljander proxies are uncalibratable due to contamination of the temperature signal by local activities, from the 1700s to the present. Critics also claim that the PNAS paper mistakenly uses two of the Tiljander proxies in an upside-down orientation, such that “warmer” information is added to the paleotemperature reconstructions as “colder”, and vice versa. In his Response published in PNAS in February 2009, Dr. Mann called these criticisms “bizarre,” but he did not explicitly rebut them.<br />
<br />
<b>Questions</b><br />
<br />
1. Can the four Tiljander proxies be calibrated to the instrumental temperature record that spans 1850 to 1995?<br />
<br />
2. Do the PNAS paper’s reconstructions use the temperature information in the “tiljander-2003-xraydenseave” and “tiljander-2003-lightsum” series in a manner that is consistent with the interpretation offered by Mia Tiljander in her 2003 paper?</blockquote>My answers to these two questions are as follows.<br />
<blockquote>1. <b>No</b>.<br />
2. <b>No</b>.</blockquote>Here's additional background. A compilation of literature and data links to this issue is <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html">here</a>. Relevant blog posts are linked <a href="http://amac1.blogspot.com/2009/11/blog-links-mann-08-and-korttajarvi.html">here</a>. One useful entry point to understanding the contrasting stances of Consensus advocates and skeptics is <a href="http://amac1.blogspot.com/2009/12/stoat-s-first-debate-on-use-of-lake.html">this digest</a> of the first <i>Stoat</i> blog post devoted to the issue. My opinion as to "why it matters" is covered in <a href="http://amac1.blogspot.com/2010/02/null-hypothesis.html">The Null Hypothesis</a>. Jeff Id of <a href="http://noconsensus.wordpress.com/">the Air Vent</a> has gone beyond Tiljander to discuss <a href="http://tinyurl.com/Google-tAV-Mann">the underlying statistical approach</a> taken by Prof. Mann's group.<br />
<br />
With that in mind, I offer these comments on Chick Keller's four points concerning Mann et al (2008).<br />
<br />
1. Mann et al (2008) is <i>not</i> careful work. It's slipshod work. The use of the Tiljander proxies is far from the only major error in the paper. It's just the glaringly obvious one. But experiences at <i>Stoat</i>, <i>Lucia's Blackboard</i> and elsewhere have shown that there's no point in discussing more complex topics if we can't first agree on simple concepts like, "Yes, the number sentence '2+2=4' is true, while '2+2=5' is false."<br />
<br />
2. It <i>is</i> good science to dismiss the way Mann et al (2008) matched proxy and instrumental data. The Tiljander proxies are uncalibratable to the instrumental record. Their misuse <i>proves</i> that these Mann group methods are grossly in error. Did Mann et al make additional mistakes at the data-compilation step? Yes, almost certainly -- but they are subtler, thus not worth considering at this point.<br />
<br />
3. To state that Mann et al is "the best work done to date on [temperatures of the past 2,000 years]" is not <i>meant</i> as a very harsh criticism of this field. Alas, I must take it that way. How did this paper pass peer review and editorial scrutiny? Why is it that in the 18 months since publication, not one "mainline" climate scientist has uttered a peep in public about it? The answers, whatever they are, cannot reflect well on practices in this branch of science.<br />
<br />
4. As far as "dismissing out of hand" -- I've been seeking out logical, data-based defenses of Mann et al's use of the Tiljander proxies for months. I have encountered none. (Readers are urged to provide candidate links in the comments to <a href="http://amac1.blogspot.com/2009/11/blog-links-mann-08-and-korttajarvi.html">this post</a>.)<br />
<br />
I invite Chick Keller to rebut these sharp criticisms of Mann et al. (2008). In particular (and as with Mann et al advocate <a href="http://rankexploits.com/musings/2010/curry/#comment-34821">Boris</a> at <i>Lucia's Blackboard</i>), I'm glad to offer him a guest post here, or a prominent link to his discussion of these questions at another location.<br />
<br />
<b>A Stark Choice</b><br />
<br />
If Chick Keller is right, high-quality paleoclimate reconstructions such as those in Mann et al (2008) can supply us with useful context for evaluating the likely effects on climate of the rising concentration of CO2. Many who share Dr. Keller's point of view also strongly believe that critics are muddying the waters with irrelevant, trivial, and incorrect objections -- perhaps out of an understandable but misguided effort to avoid facing what's needed to mitigate the climate-change threat.<br />
<br />
If I'm right, Mann et al (2008) is not simply a fatally-flawed study that's overdue for correction or retraction. Because its worst flaws are <i>obvious</i>, its privileged treatment by journal editors, peer-reviewers, the paleoclimate community, and AGW Censensus science-bloggers should serve as a bright red flag. Some practices have gone very amiss in paleoclimatology. Until those problems are identified and addressed, <i>no</i> reconstruction of the past two millenia's climate should be accorded our trust. <br />
<br />
Which is it? The best way to find out is through clear, respectful debates on the issues.<br />
<br />
I've emailed Chick Keller a link to this post.<br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com4tag:blogger.com,1999:blog-7805174.post-79566888460062213352010-02-17T07:31:00.000-08:002010-03-09T20:28:44.804-08:00The Null Hypothesis<span style="font-size: 85%;">This post is a follow-on to discussions on the use by Mann et al (PNAS, 2008) of the Lake Korttajarvi varve proxies described by Tiljander et al (2003), at <a href="http://rankexploits.com/musings/2010/unexpurgated-reasons-to-refuse-data/#comment-33269">Lucia's</a> <a href="http://rankexploits.com/musings/2010/no-statistically-significant-warming-since-1995-maybe-or-not/#comment-33771">Blackboard</a> and at Michael Tobis' <a href="http://initforthegold.blogspot.com/2010/02/grim-amusement.html?showComment=1266013954527#c2584536534250064878">Only In It For The Gold</a>.<br />
<br />
Nick Stokes <a href="http://rankexploits.com/musings/2010/no-statistically-significant-warming-since-1995-maybe-or-not/#comment-33771">asserted</a>,<br />
<blockquote>Mann fixed Tiljander in the SI of the 2008 paper. He did an analysis without it. If the calibration of the proxy doesn’t work, that’s all you can do.</blockquote>This follows in the footsteps of Gavin Schmidt's analysis at <a href="http://www.realclimate.org/?comments_popup=2019#comment-143841">RealClimate.org</a> --<br />
<blockquote>[Response: This issue was discussed ad nausem at Stoat - bring it up there... There is no other possible reconstruction that would use the proxy in another orientation. It is either in the way it was, or it isn't included at all. Both options were published together in the PNAS paper. <b>No correction needed</b>... ] </blockquote>Emphasis added.<br />
<br />
In this post, I argue that understanding the implications of Mann et al.'s use of the Lake Korttajarvi varve series is essential to a reasoned interpretation of their work.</span><br />
<a name='more'></a><br />
<span style="font-size: 85%;"><i>[Update 9 March 2010: Footnote moved to end, images added, footnote legends improved.]</i><br />
<br />
In order to undertake an informed discussion of Mann et al. (2008), one has to have a clear understanding of the presentation and use of the underlying data, <i>most especially the Lake Korttajarvi proxies</i>. <b>No correction needed</b> should be scorned as sloppy thinking and bad science. <b>Correction required!</b> is a much better slogan.<br />
<br />
Discussions with Mann's defenders about his use of the Lake Korttajarvi proxies develop a circular quality, reminiscent of the screenplay of <i>Groundhog Day</i>. <br />
<br />
Mann et al. (2008) is fine as is.<br />
X is right!<br />
Well, I grudgingly concede that you (may have) proved that X is wrong.<br />
If I were Mann, I would fix X.<br />
Mann should fix X.<br />
Come to think of it, figures like his SF8a prove that X doesn't make a difference to his results.<br />
Thus the impact of any possible correction has been shown to be trivial.<br />
Mann refused to fix X, fixing X would be trivial, thus No Correction Needed.<br />
Mann need not fix X.<br />
Mann et al. (2008) is fine as is.<br />
<br />
Let's go back to the beginning. Why did Mann and his coauthors perform this work? Why did the editors and peer reviewers of the high-prestige, high-impact journal <i>The Proceedings of the National Academy of Sciences of the USA</i> deem this work worthy of publication?<br />
<br />
The frame of reference of Mann '08's authors was:<br />
<br />
"We have a good system for extracting temperature signals out of proxies to generate paleoclimate reconstructions. Let's go well beyond bristlecone pine tree rings, and employ other proxies, as well."<br />
<br />
This led to:<br />
<br />
"The Lake Korttajarvi varve series looks like a promising paleotemperature proxy. Are its data series valid? Do the concerns of the original authors disqualify them? As careful scientists, we'll tackle this question by performing analyses both with and without these four series (Supplemental Figure 8a). We show that the reconstruction with the Lake Korttajarvi series are nearly identical (later revised to "very similar") to those without (<i>see Footnote</i>). We conclude that the Lake Korttajarvi proxies tell a story that is consistent with those told by the other proxies we've employed. The addition of data series of another provenance (lakebed sediments) and from another part of the world (central Finland) strengthens our confidence in our overall reconstruction of past climates."<br />
<br />
- - - - -<br />
<br />
Readers of Mann et al. (PNAS, 2008) have important information that the paper's authors lacked when they submitted it. <br />
<br />
We know that the Lake Korttajarvi series are among the <i>worst</i> possible data to add into a temperature reconstruction. <br />
<br />
1. Since they are uncalibratable, all four are grossly miscalibrated to the instrumental record. <br />
<br />
2. Two and probably three of the proxies were added in to the reconstruction algorithim in an upside-down orientation. Whatever "warmer" information they contain was misread as "colder," and vice versa!<br />
<br />
3. The authors thought that their proxy-qualification test (done by splitting the 1850-1995 instrumental-record period in two) showed that the Lake Korttajarvi proxies were valid. We now know that those results were entirely spurious. <br />
<br />
With hindsight, we can see that Mann and his coauthors completely misinterpreted the Lake Korttajarvi proxies. Figure SF8a in no way means what the authors thought that it meant.<br />
<br />
Instead, the use of the Lake Korttajarvi proxies constitutes a powerful test of an extremely important null hypothesis. <br />
<br />
<b>Null Hypothesis: "The combination of Mann et al. (2008)'s proxy selection protocol and computational algorithm fails to produce a valid temperature reconstruction."</b><br />
<br />
Specifically: "We have derived a paleotemperature reconstruction that we believe has merit ("NH CPS minus 7"). If we pollute the input data with spurious information to generate a pseudo-reconstruction ("NH CPS"), the pseudo-reconstruction will deviate greatly from the genuine one. Falure to show such deviation would demonstrate that the algorithm we used to construct the genuine reconstruction is refractory to corrupt, meaningless input. In that case, we would be required to accept this null hypothesis."<br />
<br />
This null hypothesis should be accepted!<br />
<br />
I am sure that there are avenues that Mike Mann can explore, where he attempts to rebut this interpretation of his reconstruction. He can run down the reasons why this formulation of a Null Hypothesis is incorrect, or why the upside-down use of the uncalibratable Lake Korttajarvi varve series does <i>not</i> sink his proxy-selection or data-analysis methodology.<br />
<br />
By all means, Mann should do so. When he submits his corrected version of Mann et al. (PNAS, 2008) as a belated response to McIntyre and McKitrick's Comment (PNAS, 2009). <br />
<br />
But returning to the extended <i>Groundhog Day</i> arguments about "No correction needed" have the effect of excusing Mann and his coauthors from facing up to their responsibilities as scientists. <br />
<br />
* The Methods should be correct, certainly as far as how key inputs were used! <br />
<br />
* The Discussion should squarely discuss the reconstructions that Mann et al generated and presented, in light of the corrupted series that they incorporated.<br />
<br />
Mann and his coauthors should not be given a pass on using <i>Proc. Natl. Acad. Sci. USA</i> as a vanity press.<br />
____________________<br />
<br />
<br />
<i><b><u>Footnote</u></b></i> -- The relative influence of the four Lake Korttajarvi proxies (and three others) can be see by contrasting the "NH CPS" (Northern Hemisphere Composite Plus Scale) trace with the "NH CPS minus 7" trace on the three Supplemental Figure 8a's that Mann has successively released.<br />
<br />
<b>Original SF8a</b> -- This is Supplemental Figure 8a as uploaded with the paper on 2 Sept. 2008. It remains unchanged (downloaded <a href="http://www.pnas.org/content/early/2008/09/02/0805721105/suppl/DCSupplemental">from the PNAS.org website</a> on 9 March 2010). The "original NH CPS" trace (green) is virtually identical with "NH CPS minus 7" trace (black).</span><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0mE8t8Lqx2RutFvd9HE9Ch-7_S0RF41GIqITVOcX_ECRSN3_4HCyQPl430VKSEBTHxZuW-xIzaem2TZrHE_rtVjV-LchJM7AleqJL81ThSzAaGXyA9r45T61coU4T54C-G6ATPw/s1600-h/Mann08-S8a-original-in-SI-080902.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="272" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0mE8t8Lqx2RutFvd9HE9Ch-7_S0RF41GIqITVOcX_ECRSN3_4HCyQPl430VKSEBTHxZuW-xIzaem2TZrHE_rtVjV-LchJM7AleqJL81ThSzAaGXyA9r45T61coU4T54C-G6ATPw/s400/Mann08-S8a-original-in-SI-080902.jpg" width="400" /></a></div><br />
<span style="font-size: 85%;"><b>Once-revised SF8a</b> -- This corrected version was uploaded to <a href="http://www.meteo.psu.edu/~mann/supplements/MultiproxyMeans07/NHcps_no7.pdf">the 'Meteo' website at Penn State</a> on 1 Dec. 2008 (it is not at PNAS.org). Text in a <a href="http://www.meteo.psu.edu/~mann/supplements/MultiproxyMeans07/">nearby directory</a> reads: "<i>UPDATE 1 December 2008: Supplementary Figure S8a had a small error due to improper calculation of the validation statistics.</i>" In this figure, "original NH CPS" (green line) is almost superimposable with "NH CPS minus 7" (black line), with the exceptions of 1020-1100, 1120-1200, 1350-1390, and 1630-1640.</span><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdbQYsKUi6lDr0V2yFtowlH9_SAM6jct21m72_PyBJUVQJzgrvMROuR6MfViS019Mlbre98AdmN4uzM1lBSSxrdwamemYWIeI-9N910hnJeXrUHs3ZuAbEc6xwD1MOkAyTw9OAtA/s1600-h/Mann08-S8a-revision1-081201-download100309.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="255" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdbQYsKUi6lDr0V2yFtowlH9_SAM6jct21m72_PyBJUVQJzgrvMROuR6MfViS019Mlbre98AdmN4uzM1lBSSxrdwamemYWIeI-9N910hnJeXrUHs3ZuAbEc6xwD1MOkAyTw9OAtA/s400/Mann08-S8a-revision1-081201-download100309.jpg" width="400" /></a></div><br />
<span style="font-size: 85%;"><b>Twice-revised SF8a</b> -- This re-corrected version was uploaded to <a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxyMeans07/NHcps_no7_v_orig_Nov2009.pdf">the 'Meteo' website at Penn State</a> on 4 Nov. 2009 (it is not at PNAS.org). Text in a <a href="http://www.meteo.psu.edu/~mann/supplements/MultiproxyMeans07/">nearby directory</a> reads: "<i>UPDATE 4 November 2009: Another error was found in the corrected Supplementary figure S8a from December 2008: The previously posted version of the figure had an error due to incorrect application of the procedure described in the paper for updating the network in each century increment. In the newly corrected figure, we have added the result for NH CPS without both tree-rings *and* the 7 potential 'problem series'...</i>" "NH CPS" (black line) is virtually identical with "NH CPS minus 7" (green line), except 1610 and 1640-1680.</span><br />
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjEQZ8Z8bZsCPrl4di9K0OBv9VOyKRq0BPueJik1MSPIhTELfvCv_GXuGdVTscbe8LY6mmRzEzbNxOm50xVQnj-u3JWB3ohUNFmUmVkE2NfLlDqUtbzSslS6rzXTuEUvA7F4VYsg/s1600-h/Mann08-S8a-revision2-091104-download100309.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="251" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjEQZ8Z8bZsCPrl4di9K0OBv9VOyKRq0BPueJik1MSPIhTELfvCv_GXuGdVTscbe8LY6mmRzEzbNxOm50xVQnj-u3JWB3ohUNFmUmVkE2NfLlDqUtbzSslS6rzXTuEUvA7F4VYsg/s400/Mann08-S8a-revision2-091104-download100309.jpg" width="400" /></a></div>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com0tag:blogger.com,1999:blog-7805174.post-49016486860247757672009-12-07T07:16:00.000-08:002009-12-07T09:17:46.609-08:00Stoat's First Debate on the Use of the Lake Korttajarvi (Tiljander) Proxies by Mann et al (2008)<span style="font-size: 85%;">There has been <a href="http://amac1.blogspot.com/2009/11/blog-links-mann-08-and-korttajarvi.html">a lot of digital ink</a> spilled on the use of the Lake Korttajarvi varve series in the long-term temperature reconstructions that are at the heart of Mann et al’s 2008 PNAS paper. Unfortunately, there haven’t been very many <i>informed conversations</i> in which the issues are discussed in a knowledgable and technically-focused manner by supporters and detractors of Mann’s uses of the proxies.<br />
<br />
Three comments threads at William M. Connolley’s blog <a href="http://scienceblogs.com/stoat">Stoat</a> come closest, in my opinion.<br />
<br />
Although a couple of obstacles became evident over the course of the three conversations there (<a href="http://scienceblogs.com/stoat/2009/10/oh_dear_oh_dear_oh_dear_oh_dea.php">Oh dear oh dear oh dear oh dear</a>, <a href=" http://scienceblogs.com/stoat/2009/10/tiljander.php">Tiljander</a>, and <a href="http://scienceblogs.com/stoat/2009/11/tiljander_again.php">Tiljander, again</a>).<br />
<br />
One is that WMC often responds to critics by inserting remarks into the middle of their arguments, making those arguments harder to follow. Another is the two-edged sword represented by his liberal comment-truncation and deletion policy: the tactic can keep conversations on track, but it can also cause the facts and reasoning marshalled by critics to appear weaker and more disjointed than is actually the case.<br />
<br />
This weekend, I reviewed the comments thread of <i>Oh dear oh dear oh dear oh dear</i>, revisiting some of the key points debated there. For context, the post itself is a mocking criticism of Roger Pielke, Jr., contending that Pielke “doesn’t’ understand” Mann et al’s use of the Lake Korttajarvi varve proxies. Most interesting is that WMC is an <a href="http://en.wikipedia.org/wiki/William_Connolley">accomplished software engineer and climate modeler</a> who has written extensively about sea ice and warming trends in the Antarctic, and who has authored posts at the flagship AGW Consensus blog <a href="http://www.realclimate.org">RealClimate.org</a> defending and defining that Consensus--prominent ongoing topics at <i>Stoat</i>. <br />
<br />
An abridged and annotated version of that post's comments thread follows the "read more" break. For clarity, I have moved WMC’s interspersed comments to the end of each comment. I have also added some of my own thoughts; these are limited to the paragraphs that begin with the text "<b>AMac 12/7/09</b>". </span><br />
<a name='more'></a><br />
<span style="font-size: 85%;">My hope is that this discussion will help readers evaluate my claims about Mann et al (2008)’s use of the Lake Korttajarvi proxies. In my opinion, there are three fundamental questions:<br />
<br />
<b>1. Did Mann et al mistakenly use some of the proxies in an upside-down fashion, relative the meaning that Tiljander et al (2003) assigned to the data?</b> (Simple question, easy answer: Yes, they did. The “xraydenseave” and “lightsum” series are inverted. The “thicknessmm” series is arguably upside-down, as well. “darksum” is right-side-up. Perhaps you are inclined to accept the Pro-AGW-Consensus argument that a data series <i>cannot</i> be used upside-down? Please read the <a href="http://amac1.blogspot.com/2009/11/newly-discovered-jarvykortta-proxy.html">Jarvykortta River proxy thought-experiment</a>, and comment there.)<br />
<br />
<b>2. Did Mann et al mistakenly calibrate the Lake Korttajarvi proxies to a time period where Tiljander cautioned that the climate signal in the data was overwhelmed by the effects of nearby human activities?</b> (Simple question, easy answer: Yes, they did.)<br />
<br />
<b>3. Are there additional fundamental problems with the logic, mathematics, and statistics that Mann et al employed in their use of the proxies to construct the multi-century temperature anomoly graphs that are at the heart of the paper?</b> (Answer: Yes, there are. Unlike the first two issues, this one is complex. It is only touched on in <i>Oh dear oh dear oh dear oh dear</i>.)<br />
<br />
WMC's post and certain illuminating comments follow.<br />
<br />
</span><b><a href="http://scienceblogs.com/stoat/2009/10/oh_dear_oh_dear_oh_dear_oh_dea.php">Oh dear oh dear oh dear oh dear</a></b><span style="font-size: 85%;"><br />
Posted on: October 27, 2009 6:46 PM, by William M. Connolley<br />
<blockquote>Please don't force me to write another of these, I'll run out of "oh dear"s.<br />
<br />
The issue is RP Jr <a href="http://rogerpielkejr.blogspot.com/2009/10/point-resolved-in-hockey-stick-wars.html">venturing into areas of climate science he doesn't understand</a> (see <a href="http://scienceblogs.com/stoat/2008/05/losing_the_plot.php">losing the plot</a> for the last one I remember) and dragging <a href="http://cruelmistress.wordpress.com/2009/10/26/peer-review-game-on/">Cruel Mistress along behind</a>, though to be fair CM doesn't fully commit herself.<br />
<br />
<a href="http://rogerpielkejr.blogspot.com/2009/10/point-resolved-in-hockey-stick-wars.html?showComment=1256594440835#c6742601215885761273">AndrewT has already explained the truth to Roger</a>, but it doesn't look like he wants to know it :-(.</blockquote><br />
[<b>AMac 12/7/09</b>: I snipped a few "off-topic" concluding sentences from the original post.]<br />
<br />
<b>Comments to "Oh dear oh dear oh dear oh dear"</b><br />
<br />
Comment 9 | Posted by AMac | October 27, 2009 10:56 PM<br />
<blockquote>I'm a lay person who was intrigued by Roger Pielke's account and the discussion in his comments. I pulled the Mann et al. (2008) PNAS paper and Supporting Information, which led to a some questions, and considerable puzzlement. I posted them as a two-part comment over there, <a href="http://tinyurl.com/yab4jps">#35</a> and <a href="http://tinyurl.com/ya693v6">#37</a>.<br />
<br />
To me, the heart of the matter seems to be this. Mann et al. used a series of 15 time-series data sets (Fig. S9) to derive a “Temperature Anomaly vs. Time” graph for the Northern Hemisphere (Figs. 2 and 3). It turns out (Mcintyre claims that) that Mann et al. made an error in handling one of the 15 proxies (Tiljander's X-Ray Diffraction measures of the Lake Korttajarvi varve series). Mann et al. assumed that lower XRD values signify cooler temperatures, whereas Tiljander and others assign lower XRDs to warmer temperatures.<br />
[WMC #1]<br />
<br />
In addition, Tiljander states that the four Lake Korttajarvi records (XRD and three other varve characteristics) are unreliable after about 1720 because of nearby human activity. Peat ditch-cutting in 1930 and bridge construction in 1967 are the causes of the most prominent recent variances in three of the four records, clearly visible in Fig. S9.<br />
[WMC #2]<br />
<br />
How is it possible to remove these four records (and three others), leaving eight proxy series for the Northern Hemisphere, and end up with a Temperature Anomaly reconstruction that is indistinguishable from the one constructed from all fifteen proxy series (Fig. S8a, green vs. black line)?<br />
[WMC #3]<br />
<br />
Mann seems to be saying that reversing one of the fifteen proxies (mistakenly correlating higher XRD with higher instead of lower temperature) doesn't alter the temperature reconstruction. How can this be? If the varve XRD proxy is inconsequential, why include it at all?<br />
[WMC #4]<br />
<br />
Could any of the other 14 proxies have their polarity reversed without effect? How about two? three?...<br />
[WMC #5]<br />
<br />
This doesn't make sense to me.<br />
[WMC #6]<br />
<br />
<b>WMC inline responses: </b><br />
#1 - OK, yes. This is the assertion that the series is “upside down”. Mann et al. (and I) claim this doesn't matter.<br />
<br />
#2 - This is a different - though important in its own right - matter. It may be peripherally related.<br />
<br />
#3 - That would require various bits of analysis which I can't readily do to answer. But I can offer a hand-wavy answer. Suppose the lake sediments have been so affected by recent (non-climatic) changes that they are just random noise. then their correlation against recent temperature will be essentially zero. So their contribution to the reconstruction will be very small. You can (I speculate) extend this argument to a large number of proxies: you can throw in any number of series with no idea of their correlation to temperature, and the method will (on average) sort them all out. Of course, if *none* of your records usefullly records temperature you won't get anything interesting out.<br />
<br />
#4 - No, you've misunderstood. Its not that its inconsequential, just insensitive to sign. See my helpful formula in one of the comments higher up.<br />
<br />
#5 – All.<br />
<br />
#6 - And yet it is not that difficult. Maybe I need to blog this.<br />
<br />
<b>AMac 12/7/09</b>: Response #1 suggests that WMC has waded into this discussion without understanding the gravity of Mann et al’s problems with the Lake Korttajarvi proxies. (At this early stage, I didn’t, either.) In response #2, WMC is already failing to defend Mann et al’s calibration of the varve series. This is (or should be) fatal to their use, even if all of them had been used right-side-up. The point about corrupt proxy data leaving the temperature traces in Mann et al Figure S8a unaffected speaks to the other major defects in Mann et al’s paleoclimate reconstructions. In responses #4 and #5, WMC is completely incorrect: using a thermometer upside-down is <i>fatal</i> to temperature reconstructions. </blockquote><br />
Comment 10 | Posted by: Rattus Norvegicus | October 28, 2009 12:21 AM<br />
<blockquote>AMac,<br />
<br />
I suggest you take a look at figure 1 in the <a href="http://www.pnas.org/content/105/36/13252.full?sid=660b6b81-20d0-485c-a254-c8b4e1dcd079">actual paper</a>. This shows the distribution of proxies in the data he used. It was over 1200 in total more than 400 passed the local temperature screen. Dropping 4 or even 8 series from this (series which Mann admits in the SI to be problematic) reconstruction would obviously have little effect on it, contrary to McI blowing this up into some case which should be heard in the war crimes court at the Hague.<br />
<br />
As far as how the two recons are virtually identical, in the modern period hundreds of proxies are in use and so the effect of these problematic proxies is small. The larger effect is probably seen in the error bars associated with values in the 9th and earlier centuries, take a look at Figure S10 which shows the effects better due to the expanded scales used.<br />
<br />
<b>WMC response:</b> I'd rather this didn't broaden out into the usual discussion of the validity of the reconstructions. This should focus on the narrow point: does the sign of the proxies matter. So far the only serious objection I've seen is “it doesn't matter for Regem but does for CPS”. Anyone with an informed view on that is welcome to comment. </blockquote><br />
Comment 11 | Posted by: AMac | October 28, 2009 1:46 AM<br />
<blockquote>Thanks, Rattus Norvegicus! I see that I'm asking about a smaller issue (the 15 screened proxies available for the NH CPS reconstruction back to the 9th century and earlier, end of pg. 13255 ff). Your point on the broader issue is that there are much, much larger numbers of proxies available for more recent times (red symbols in Fig. 1).<br />
<br />
McIntyre claims that all four of the Lake Korttajarvi varve proxies had their signs reversed in Mann et al (2008), not just the XRD one.<br />
<br />
Thus, I remain perplexed by Fig. S8a. That depicts the NH Land Temperature Anomaly reconstructions, performed (1) with the full proxy network (green line), and then (2) with the eight proxies remaining after the removal of seven potentially problematic series (black line).<br />
<br />
The full proxy network would be the fifteen NH proxy records that pass the screening procedure back to AD 818 or earlier, shown on Fig. S9. Of the seven removed for the black line, four are the four flipped-around Lake Korttajarvi series. Yet the two reconstructions look almost identical, from 200 AD through to 2000 AD.<br />
With so few proxy series, shouldn't this removal have led to a very different-looking curve?<br />
<br />
(I'll cross-post this at Pielke's blog.)<br />
<br />
<b>AMac 12/7/09</b>: In this comment, I incorrectly stated that all four Lake Korttajarvi proxies were used upside-down with respect to the orientations proposed by Tiljander et al. Actually, two were upside-down, one is ambiguous, and one is right-side-up. </blockquote><br />
Comment 12 | Posted by: andrewt | October 28, 2009 1:49 AM<br />
<blockquote>AMac, yes if a method is insensitive to sign, you should be able to reverse the polarity of any or all of the inputs and the output should remain unchanged. As Marcus says above, this does seem to raise other questions - which sadly you might actually need to know something about paleoclimatology to consider.<br />
<br />
In truth I was more fascinated by Roger wading into paleoclimatology after his recent railing that the professionally-unqualified should not be debating his work.<br />
<br />
<b>AMac 12/7/09</b>: AndrewT is correct, but only in detail. In the case of two of the Lake Korttajarvi proxies, the outputs may indeed remain unchanged—but they are inverted with respect to Tiljander’s assignments! Again: reading a thermometer upside-down is <i>fatal</i> to a climate-reconstruction project. </blockquote><br />
Comment 14 | Posted by: AMac | October 28, 2009 7:23 AM<br />
<blockquote>andrewt, thanks.<br />
<br />
> if a method is insensitive to sign, you should be able to reverse the polarity of any or all of the inputs and the output should remain unchanged.<br />
<br />
As a general statement, this is certainly true, and it seems to apply to the four upside-down Lake Korttajarvi varve proxies and the reconstruction in Figure S8a. But that's what puzzles me: what, exactly, does Figure S8a show?<br />
<br />
<b>WMC response:</b> Cut. Sorry, perfectly sensible comment, but not on the (restricted) topic. <br />
<br />
<b>AMac 12/7/09</b>: The full text of the comment is at <a href="http://tinyurl.com/yjflxfr">this cross-post</a>.</blockquote><br />
Comment 15 | by road | October 28, 2009 7:23 AM<br />
<blockquote>You guys are missing the point here.<br />
<br />
Yes, the sign going into a multivariate regression doesn't matter. But the sign coming out certainly does. And if the correlation coming out has a sign opposite to the a priori physical meaning, then we have a problem. That means the correlation is aphysical and spurious.<br />
[WMC #1]<br />
<br />
The CPS method used by Mann (one of two methods he used) is not a multivariate regression. As described by CA “CPS is little more than averaging and shouldn't take more than a few lines of code. You standardize the network - one line; take an average - one more line; and then re-scale to match the mean and standard deviation of your target - one more line.”<br />
<br />
So, the sign clearly does matter.<br />
[WMC #2]<br />
<br />
Guys, this one is a no-brainer.<br />
<br />
<b>WMC inline responses: </b><br />
#1 - The sign going in is the point at issue here. If the sign going in is wrong, then the correlation has the same absolute value but the wrong sign, which means the series gets added back in to the reconstruction with the sign wrong twice, ie correctly. If by “the correlation is aphysical” you mean, of the wrong sign, then you are correct. But this is irrelevant.<br />
<br />
#2 - I'm unsure what you mean by that. You're clearly wrong on your point 1 - are you applying this “no-brainer” comment to yourself? On point 2 there is unclarity, but simply relying on CA to tell you the truth seems unwise.<br />
<br />
<b>AMac 12/7/09</b>: Road’s analysis is correct. WMC’s rebuttal is nonsensical. Reading a thermometer upside-down <i>does</i> matter. </blockquote><br />
Comment 16 | Posted by: Peter | October 28, 2009 7:52 AM<br />
<blockquote>Point #15 clears this up quite nicely. Since Kaufman has issued a Corrigendum in which the upside down series is acknowledged, is he wrong or is Mann?<br />
<br />
<b>WMC response:</b> He is right and Mann is right.<br />
<br />
<b>AMac 12/7/09</b>: WMC’s response is again nonsensical. Kaufman followed Mann’s lead and read a thermometer upside-down. When this was brought to his attention, he corrected the error. Kaufman and Mann <i>cannot</i> both be correct. </blockquote><br />
Comment 17 | Posted by: jeff id | October 28, 2009 9:30 AM<br />
<blockquote>#8 William,<br />
<br />
CA has replicated the whole CPS portion of the study. In the case of CPS the ambiguous proxy is flipped according positive or negative correlation. I'll dig through the code later if I get a chance and point to the exact line where the flipping occurs or doesn't. When CPS is finished you have a multiplier vector 'a' times array 'Ta' for each proxy. The sum of the array after multiplication times a is the result - flipped proxy!<br />
<br />
In the case of EIV the process is a 'best fit' of proxies to the temp record - iterative multivariate regression through expectation maximization.<br />
<br />
If you took 100 downslope tiljanders + a small amount of noise and fit them to an upslope temp record, they would mostly flip upside down matching the temp rise with a probability that some were used upside right. The net sum would give a best match to the temperature upslope even though 100 percent of the data had the original Tiljander downslope initially.<br />
<br />
Of course despite the match to instrumental records, the important historic result would have very little to do with temperature and were the proxy related to temperature, the historic portion would represent anti-Tiljander temperature after averaging.<br />
<br />
It's really a very very dead issue.<br />
<br />
<b>AMac 12/7/09</b>: Jeff Id’s analysis is correct and has stood the test of time. </blockquote><br />
Comment 18 | Posted by: David | October 28, 2009 10:19 AM<br />
<blockquote>“If by ‘the correlation is aphysical’ you mean, of the wrong sign, then you are correct. But this is irrelevant -W"<br />
<br />
How can it be irrelevant that a proxy reconstruction is inverting constituent proxies with a known (or presumed) physical correlation to that which the reconstruction is attempting to reconstruct ?<br />
<br />
<b>WMC response:</b> Cut. Answer: read the stuff above.<br />
<br />
<b>AMac 12/7/09</b>: There is no adequate rebuttal to David’s points, earlier (or later) in this thread.</blockquote><br />
Comment 19 | Posted by: Jason | October 28, 2009 10:28 AM<br />
<blockquote>William, are you seriously defending Mann's use of Tijander with the given orientation?<br />
<br />
<b>WMC response:</b> Trimmed. If you've read what I've written before, you know the answer to that. </blockquote><br />
Comment 23 | Posted by: AMac | October 28, 2009 12:40 PM<br />
<blockquote>The validation period for the 15 screened NH CPS proxy series was 1850-1995 (pg. 13254). Tiljander states that natural signals in the Lake Korttajarvi varve proxies are disrupted after ~1720 by nearby human activities (SI, pg. 2). Thick, mineral-rich varves due to ditch-cutting in 1930 and bridge-building in 1967 are prominent in Fig. S9.<br />
<br />
The CPS method was applied in three different ways. Full CPS (calibration 1850-1995), Early (1850-1949) Calibration [Validation 1950-1995], and Late (1896-1995) Calibration [Validation 1850-1895] (pg. 13254).<br />
The Full, Early, and Late 15-proxy reconstructions have the same general shape from 400 to 1850, though there are periods of divergence prior to 1700 (Fig. S11a).<br />
<br />
For the varve proxy series, all three CPS calibration approaches appear to have led to the correlation of the deposition of thick, mineral-rich varves with higher temperatures.<br />
<br />
Thus, it would appear that the four Lake Korttajarvi proxies contributed a “warmer” signal to the 400-1850 CPS reconstructions in the decades when varves were thicker and more mineral-rich. And a “cooler” signal when varves were thinner and included more organic material. (See orientation of Tiljander proxy plots in Fig. S9, and CPS curves in Figs. 2, 3, S7, S8, S10, & S11.)<br />
<br />
This appears to be the opposite interpretation to the one offered by Tiljander, who correlates thinner, more organic-rich varves with higher temperatures. Kaufman accepts Tiljander in his 10/9/09 correction.<br />
<br />
If this description is correct, it would appear that there is a “sensitivity to sign” in the CPS method of analyzing climate proxies to derive reconstructions of hemispheric temperature anomalies. <br />
<br />
<b>AMac 12/7/09</b>: This description is correct.</blockquote><br />
Comment 25 | Posted by: William [Connolley] | October 29, 2009 4:51 AM<br />
<blockquote>Commenting on my own post... how gauche. Anyway, over at CM is an intersting and perhaps enlightening comment by Bender, which may indicate that the entire debate is shifting. I don't know if this is merely B's viewpoint, or if the CA types have realised that the “upside down” charge in its original form won't fly. I'll copy my reply, which I think quotes B's main points:<br />
<br />
The substantive issue is how does Mann’s code treat a proxy when its relationship with temperature changes as you move from the calibration phase into the reeconstruction phase. Aha! Thank you. This is the first time someone has made a coherent argument over this (perhaps it has been said before but lost in the noise, if so my apologies for missing it).<br />
<br />
I would answer that such a proxy is simply useless. Getting the sign of the overall series right would not make it useful. A proxy with the properties you describe should not be used.<br />
<br />
And it’s not a statistical issue; it’s a coding issue I disagree. It is a data-source issue.<br />
<br />
Mann should have investigated more thoroughly once he’d seen the McIntyre complaint – not sure about that. McI’s complaint (assuming we’re talking about the same text) was: “Their non-dendro network uses some data with the axes upside down, e.g., Korttajarvi sediments, which are also compromised by agricultural impact (M. Tiljander, personal communication), and uses data not qualified as temperature proxies (e.g., speleothem δ13C). “ If he meant what you said, he could and should have said so.<br />
<br />
Incidentally, “which are also compromised by agricultural impact (M. Tiljander, personal communication)” is an interesting phrase – this appears to imply that the compromise wasn’t clear without pers comm. <br />
<br />
<b>AMac 12/7/09</b>: In other comments (search ClimateAudit.org), bender has unambiguously asserted (1) that Mann et al used Lake Korttajarvi proxies in an upside-down manner, and (2) that it would be impossible to calibrate the proxies to the instrumental record. In her 2003 paper, Tiljander discusses the overwhelming non-climate signals in the varves in recent times--some of these cautions are quoted by Mann et al (2008) under “Potential data quality problems” (Supporting Information, page 2). Knowledge of these issues is not limited by "personal communications."</blockquote><br />
Comment 26 | Posted by: Jason | October 29, 2009 10:36 AM<br />
<blockquote>William, you're missing the basic point here.<br />
<br />
A temperature reconstruction is _supposed_ to be a logical argument which shows that, as long as a certain set of assumptions hold, past temperatures may be characterized by a calculated curve.<br />
<br />
The problem with Tiljander is not that Mann somehow miscalculated. The problem is that the basic assumptions which give Mann's calculations meaning have been violated.<br />
<br />
Mann's logical argument assumes that the relationship between Tiljander and local temperature has been uniform during the period for which its signal has been used. This is plainly (and in this case spectacularly) false.<br />
<br />
During the period for which we have instrumental temperature readings, the Tiljander signal is dominated by non-temperature related anthropogenic activity (building bridges, etc.). During earlier periods it is believed (by the people who collected the data) to be correlated with temperature in the opposite direction of what Mann has used.<br />
<br />
The end result, is that warmer MWP temperatures in Finland cause Mann's temperature reconstruction to go down, and visa versa.<br />
<br />
To the extent that Mann would attempt to use his reconstruction to make arguments about current temperatures compared to MWP temperatures (unprecedented in the last 2000 years kind of arguments), his argument is logically flawed.<br />
<br />
In summary, the people who are saying that the proxy is upside down are NOT saying that Mann made an arithmetic error. They are saying that, due to modern artifacts, several (heavily weighted) components of Mann's calculation have a negative correlation with temperature.<br />
<br />
If Mann's curve does not represent past temperature, then its not a temperature reconstruction.<br />
<br />
<b>AMac 12/7/09</b>: A consise, logical, and correct argument. </blockquote><br />
Comment 28 | Posted by: bernie | October 29, 2009 11:29 AM<br />
<blockquote>William, you wrote:<br />
<br />
“The proxy is correlated against the instrumental record before being amalgamated into the global record. So T_glob = avg(Proxy_i * corr(Proxy_i, T_ins)) (it isn't, but its like that. Avg() is over i, corr is over the period of the instrumental record, the proxy series is assumed to run over a longer period). So if you reverse the sign of Proxy_i, it makes no difference at all to T_glob”<br />
<br />
Given your articulation of the calculation, you are correct only if the corr(Proxy_i, T_ins) is moreorless constant through the full time period covered by Proxy_i.<br />
[WMC #1]<br />
<br />
Since Tiljander clearly indicates that the true relationship is swamped and in fact reversed by local non-temperature related activities in the recent period then (a) Mann should have excluded this proxy and (b) using it produces as spurious and as misleading a relationship as using the annual consumption of firewood in Finland over the last 500 years. It is simply a gross error and Mann (and you) should simply acknowledge it.<br />
[WMC #2]<br />
<br />
<b>WMC inline responses</b><br />
#1 - No, you've misunderstood. That corr is a single number, and is thus constant by definition. Were you under the impression that it was some kind of time-dependent running correlation?<br />
<br />
#2 - If the proxy represents non-climate information then it shouldn't be used. But I've already said that, so I'm not sure why you want me to say it again. But now I have - are you hap-hap-happy?<br />
<br />
<b>AMac 12/7/09</b>: According to Tiljander, there is no “if”--climate information in the Lake Korttajarvi data series <i>is</i> overwhelmed by non-climate influences in the late eighteenth, nineteenth, and twentieth centuries. This makes calibration to the instrumental record impossible. Thus, Mann used these proxies incorrectly (including the one or two of the four that was not upside-down). </blockquote><br />
Comment 30 | Posted by: Rattus Norvegicus | October 29, 2009 1:36 PM<br />
<blockquote>A quick question.<br />
<br />
AMac, you assert that in Finland colder temps lead to greater snowpack, however warmer air tends to hold more moisture and result in greater precipitation. For example, here in Montana we get our heaviest snowfalls when temps are just below freezing. When temps lower into the teens, even in the midst of a storm, snowfall amounts are typically less and the water content of said snow is nil. Since we live in a rather dry continental area this relationship might not hold true in Finland, but given what I know about snowfall and snowpack in Montana I would hazard that warmer winters might lead to greater snowpack and a larger snowmelt. There are also some confounding factors associated with late spring (or runoff season) temps. A good hot streak can cause rapid snowmelt which really loads up the rivers around here with sediment and shortens the runoff season. More normal temps during snowmelt extend the runoff season and the rivers have a lower sediment load. Of course these observations are strictly local in nature, but around here my guess would be that warmer temps would be indicated by thicker lake bed sediment deposition and colder temps by less deposition. Are you sure that you are correct about the way that Tiljander interpreted the thickness proxy and not the non-organic/organic matter proxies? </blockquote><br />
Comment 31 | Posted by: jeff id | October 29, 2009 1:41 PM<br />
<blockquote>#25, You have to give McIntyre some room in his reply to PNAS the study had many flaws and everything had to fit inside 250 words.<br />
<br />
Mann realized that the proxy was used upside down. I understand bender's comment but it seems simple enough to me that when you invert the scale on your thermometer it ain't temp anymore. Explaining the reason for the inversion was due to local environmental factors (which were pointed out by the Tiljander authors) and careless use of algorithms is another issue entirely.<br />
<br />
Flipping an alleged temperature curve upside down and averaging with other alleged temperature curves is an obvious mistake...<br />
<br />
#29, In the CPS method the orientation of the data does make a difference. In the EIV method it does not. Therefore, it does make a difference in the final result of the CPS method for certain, however we would need to see the resulting weight factors of EIV to determine if it was inverted there.<br />
<br />
Now with all that said, EIV is trying to find the best fit. Since we have to invert tiljander to achieve an upslope and positive correlation it's highly likely that EIV also created the same problem.</blockquote><br />
Comment 32 | Posted by: AMac | October 29, 2009 2:05 PM<br />
<blockquote>Rattus Norvegicus wrote (1:36pm) –<br />
<br />
> [AMac], Are you sure that you are correct about the way that Tiljander interpreted the thickness proxy and not the non-organic/organic matter proxies?<br />
<br />
I'm certainly not sure that I'm correct about Tiljander's interpretation! In fact, I have wondered the same thing. I'm a lay person (who was a long-ago geology major). I've never even been to Scandanavia.<br />
<br />
However, I paraphrased Tiljander's interpretation of the data, which McIntyre reports has been supported by other Finnish scientists working in this area, and now by Kaufman.<br />
<br />
It seems to me that the burden falls on Mann et al to explicitly state and defend a contrarian interpretation, if they are going to base reconstructions on it.<br />
<br />
Read Mann et al's SI Methods treatment of the possible post-1720 unreliability of the varve record. They don't raise this issue, and imply (in my opinion) that they follow the standard interpretation.<br />
<br />
I find it very unlikely that Mann et al realized that their algorithm imposed the opposite interpretation on the varve data. If they had, I think they would have dropped the varve proxies.</blockquote><br />
Comment 34 Posted by: Sean Houlihane | October 29, 2009 5:17 PM<br />
<blockquote>I find it very interesting that the discussion is focusing on the sign of the proxy which is being discussed. It seems bizarre that this is viewed as the substantive issue when it does appear fairly clear that the proxy is not suitable for use due to contamination of the modern period - a fact which seems to be quite plain once the sign and coefficient of the proxy's contribution to the reconstruction are known (or guessed).<br />
<br />
Is this a game of semantic point scoring, or is a discussion of the validity of this proxy in this specific method relevant here?<br />
<br />
<b>WMC response:</b> This post, as the title rather suggests, was written in response to RP's confusion. The main aspect of that appeared to be his misunderstanding of the “upside down” issue. The issue of whether this particular proxy is of any use or not is another matter, doubtless fascinating in itself <br />
<br />
<b>AMac 12/7/09</b>: There are no indications that Pielke was confused as far as the upside-down usage by Mann et al of two of the Lake Korttajarvi proxies. Pielke’s understanding was correct. </blockquote><br />
Comment 38 Posted by: PaulD | October 30, 2009 3:30 PM<br />
<blockquote>“Is this a game of semantic point scoring, or is a discussion of the validity of this proxy in this specific method relevant here?”<br />
<br />
This comment strikes me as dead on. The essence of SM's point is that Mann's algorithm misused the proxy by orienting it during the reconstruction period in a manner opposite of the physical theory that justifies its use as a temperature proxy. That is what SM meant by saying it was used “upside down” and I think that he certainly makes this clear on his blog, but perhaps less so in his published comment with its space limits. I also understand that “multivariate regression methods are insensitive to the sign of predictors.” The statement is true and entirely beside the point of SM's criticism.<br />
<br />
I've read Pielke's post and it is clear to me that he understands SM's argument. He may have been confused by the statement, “Multivariate regression methods are insensitive to the sign of predictors.” I can also understand why his “confusion” arose, because I was similarly confused at first. He likely thought, as I did intitially, that the statement was responsive to SM's criticism, whereas it is actually a dodge, perhaps made intentionally or quite possibly based on a misinterpretation of SM's brief published comment.<br />
<br />
The bottom line, however, is that I think it is unfair to criticize Pielke when he accurately understood the major point of the controversy, although he may have been a little confused on a technical statistical issue that is ultimately irrelevant.<br />
<br />
<b>WMC response:</b> You're welcome to your opinion, of course, but I see nothing in Pielke's post that suggests he has a clue. What makes you think he “accurately understood the major point of the controversy”? As for "may have been a little confused on a technical statistical issue" I think you're being very generous.<br />
<br />
<b>AMac 12/7/09:</b> PaulD’s characterization is succinct and correct, in my opinion. </blockquote><br />
--- End Abridged <i>Stoat</i> Comment Thread ---<br />
<br />
<b>Summary: Pro-AGW-Consensus scorecard</b> <br />
<br />
My view of the position of WMC (and the other technically-savvy pro-AGW-Consensus bloggers and commenters who contributed to the <i>Oh dear oh dear oh dear oh dear</i> thread) on the way that Mann et al (PNAS, 2008) used the Lake Korttajarvi varve proxies.<br />
<br />
<table align="center" border="1" cellpadding="1" cellspacing="0"><tbody>
<tr><td><b>Issue</b></td><td><b>Problem Acknowledged?</b></td><td><b>Call for Correction?</b></td></tr>
<tr><td>1. Upside-Down Proxies</td><td>No </td><td>No</td></tr>
<tr><td>2. Wrongly-Calibrated Proxies</td><td>Yes (equivocally)</td><td>No</td></tr>
<tr><td>3. Other Major Problems with <br />
Temperature Reconstructions</td><td>To be determined</td><td>No</td></tr>
</tbody></table></span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com8tag:blogger.com,1999:blog-7805174.post-17639392126269348852009-11-29T12:00:00.000-08:002010-03-15T07:49:42.831-07:00Off-topic Thoughts Addressed to a Dendrologist Visiting Climate Audit<span style="font-size: 85%;">At about the 113rd comment, a dendrologist entered the thread of <a href="http://www.climateaudit.org/?p=7747">Miracles and Strip Bark Standardization</a> at ClimateAudit.org. "CB" <a href="http://www.climateaudit.org/?p=7747#comment-366848">began</a>"<br />
<blockquote>November 23rd, 2009 at 4:30 pm<br />
<br />
I have to agree with Rob Wilson - most of this discussion reveals a fundamental lack of understanding and experience with the subject [of strip bark analysis]...</blockquote>Happily, CB returned to address technical issues in dendrology and climate reconstruction. </span><br />
<a name='more'></a><br />
<span style="font-size: 85%;">At <a href="http://www.climateaudit.org/?p=7747#comment-367351">Comment #195</a>, I wrote<br />
<blockquote>CB --<br />
<br />
Thanks again for coming and addressing dendro-related issues, and for providing links to what you view as the literature's "best of" summaries. Given the apparent state of the dendrochronology and climatology professions, it shows considerable integrity that you're here. I'm read-only on the methodology you describe, but I (along with other lurkers, I'd wager) am learning.</blockquote>Continues...<br />
<br />
<a href="http://www.climateaudit.org/?p=7747#comment-367270">You wrote</a>, "It is a little unfortunate that I am in the position of the lone gunman facing the militia here." Well: Not exactly. In the physical science specialties I'm familiar with, vigorous debate on technical issues is <i>expected</i> (You never attended any of our lab meetings or journal clubs in cell/molecular biology). It has become evident to me that paleoclimatology and dendrochronology are unusually insular areas of inquiry. "Everyone who is anybody" agrees on certain foundational principals, allowing the field to keep advancing, e.g. with ever-more-precise temperature reconstructions. It comes as a rude shock to find intelligent, knowledgeable outsiders who do <i>not</i> adhere to these concepts.<br />
<br />
In that regard, <i>you dendros and paleos are traveling a well-worn path</i>. Example: Breast cancer surgeons, 1900-1975. I've put <a href="http://amac1.blogspot.com/2009/11/norman-wolmarks-perspective-on-history.html">Dr Norman Walmark's recent talk</a> up. His concerns are very different from mine, but you can get the point. Surgeons following in Halstead's footsteps concerned themselves with the details of the surgical techniques of the radical mastectomy, and properly so. But in keeping their focus narrow, they lost sight of the most important questions <i>for three-quarters of a century</i>. A quantitative example: reliance on sophisticated models of the riskiness of collateralized mortgage obligations was a key contributing factor to the onset of the 2008 financial meltdown.<br />
<br />
A chasm has developed between the analytical approaches that are considered acceptable in dendro/paleo, and those that constitute a minimum in certain other fields. Speaking as one familiar with interpretation of clinical trials, the dendro/paleo standard is at least a decade behind. In some disputes, positions analogous to those taken by prominent people in your field are <i>discredited</i> elsewhere. E.g. compare the current extremely permissive dendro/paleo consensus views on "data selection" and "post hoc analysis" with the sophistication attending the <a href="http://www.ncbi.nlm.nih.gov/pubmed/10822117">intent-to-treat</a> approach to clinical trials (that's a 9-year-old article). You dendros and paleos would greatly benefit from recruiting some up-and-coming biostatisticians into your laboratories, and heeding their advice.<br />
<br />
The reception of the Mann et al (PNAS, 2008) paper has revealed the very poor health of the dendro and paleo communities. This was a high-profile paper by a heavy-hitting scientist in one of the world's most prominent peer-reviewed journals. Yet the paper is a travesty. Opaque data and computer code, slovenly peer review, incorrect calibration, upside-down transposition of multiple climate proxies, erroneous figures, failure to disclose methodology... the list goes on. (Do you agree?) And the response of dendrochronologists and paleoclimatologists has ranged between Silence and Acceptance. For whatever reasons, dendros and paleos have been incapable of voicing criticism, no matter how tawdry the details. E.g. note the cheerleading by pro-Consensus voices <a href="http://amac1.blogspot.com/2009/11/blog-links-mann-08-and-korttajarvi.html">here</a>. Perhaps most of you folks are unaware of how far your standards have fallen. Perhaps most of you are more concerned with policy, politics, and professional prospects than some distant Olympian ideal. I don't know. <br />
<br />
That's my view of the context of the discussion of strip bark tree analysis. Again, thanks for sharing your perspective. In engaging the CA commentariat, I hope you find that you have learned as well as taught.</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com0tag:blogger.com,1999:blog-7805174.post-20376226859645246122009-11-29T07:26:00.000-08:002011-08-17T07:53:19.805-07:00Primary Links: Mann '08 and the Korttajarvi (Tiljander) Proxies<span style="font-size: 85%;">I'm compiling links to webpages that address the controversy surrounding Mann et al (2008)'s use of the lakebed sediment record from Lake Korttajarvi, Finland in their reconstructions of global climate, 200 AD to 1850. <br />
<br />
See also <a href="http://amac1.blogspot.com/2009/11/blog-links-mann-08-and-korttajarvi.html">Blog Links: Mann '08 and the Korttajarvi (Tiljander) Varve Proxies</a></span><br />
<a name='more'></a><br />
<span style="font-size: 85%;">Please add missing URLs in the comments. Since it's a compilation with little editorial content, this post may be updated without notice.<br />
<br />
<b>The Lake Korttajarvi Borehole</b><br />
<br />
<a href="http://maps.google.com/maps?q=62.3318,25.6821">Google Maps view</a> of Lake Korttajarvi borehole at Lat 62.3318, Long 25.6821<br />
<br />
<a href="http://tinyurl.com/ycc9tvu">Finnish-language map of Lake Korttajarvi</a><br />
<br />
Mia Tiljander, M Saarnisto, AEK Ojala, and T Saarinen. "A 3000-year palaeoenvironmental record from annually laminated sediment of Lake Korttajarvi, central Finland." Boreas 26:566–577, 2003. [Update 14 March 2010: PDF <a href="http://www.climateaudit.info/pdf/others/Tiljanderetal.pdf">archived at ClimateAudit.<i>info</i></a> (not ClimateAudit.org). Abstract <a href="http://www3.interscience.wiley.com/journal/119823104/abstract?CRETRY=1&SRETRY=0">at the Wiley website</a>.]<br />
<br />
<a href="http://ethesis.helsinki.fi/julkaisut/mat/geolo/vk/tiljander/">Mia Tiljander.</a> "Holocene sedimentary history of annual laminations of Lake Korttajärvi, central Finland." PhD Dissertation, University of Helsinki, Dept. of Geology, Geology and Palaeontology. October 2005. <i>Archived PDF.</i> Includes the quote, "Since the early 18th century, the sedimentation has clearly been affected by increased human impact and therefore not useful for paleoclimate research." (pg. 24).<br />
<br />
<a href="ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/finland/korttajarvi2003.txt">Lake Korttajärvi, Finland 2000 Year Varved Sediment Data</a>, <i>NOAA text-file FTP archive,</i> updated Sept. 2009. "Mineral", "Organic", and "X-Ray Density" values, 0 - 1985. [<b>UPDATE</b> 8/16/11 -- for the year 1326, values for Lightsum and Darksum (and thus Thickness, as well) are anomalous, over tenfold higher than any neighboring year. Somehow, in the files archived at the Mann website, these numbers have been overwritten by the average of the values for 1325 and 1327.]<br />
<br />
<a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/Tiljander-Korttajarvi-raw-data.csv">NOAA text-file data in ".csv" format</a>, uploaded Nov. 2009 to BitBucket.org<br />
<br />
<a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/">AMac's downloadable files at BitBucket.org</a>. <i>See the directory's summary.</i><br />
<br />
<br />
<b>The Mann et al (2008) PNAS paper, Supporting Information, Comments, and Data Archives</b><br />
<br />
<a href="http://www.pnas.org/content/early/2008/09/02/0805721105">Michael E Mann</a>, Zhihua Zhang, Malcolm K Hughes, Raymond S Bradley, Sonya K Miller, Scott Rutherford, & Fenbiao Ni. "Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia." PNAS 105:13252–13257, Sept. 9, 2008. Published online Sept. 2, 2008. Received for review Nov. 20, 2007. Communicated by LG Thompson, OSU. <i>PNAS web page with full text as HTML and PDF, Supporting Information as PDF</i><br />
<br />
<a href="http://www.pnas.org/cgi/content/full/106/6/E10">S McIntyre & R McKitrick</a>. "Proxy inconsistency and other problems in millennial paleoclimate reconstructions." PNAS 2009 106:E10, online publication 2 Feb. 2009. <i>PNAS web page with full text as HTML and PDF</i><br />
<br />
<a href="http://www.pnas.org/content/106/6/E11.full">ME Mann, RS Bradley, & MK Hughes</a>. "Reply to McIntyre and McKitrick: Proxy-based temperature reconstructions are robust." PNAS 2009 106:E11, online publication 2 Feb. 2009. <i>PNAS web page with full text as HTML and PDF</i><br />
<br />
<a href="http://www.meteo.psu.edu/%7Emann/Mann/">Prof. Mann's main Penn State University page</a><br />
<br />
<a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxyMeans07/">Mann's Penn State page</a> for Mann et al (2008) Supplemental Information and Data, updated Nov. 4, 2009<br />
<br />
<a href="http://www.ncdc.noaa.gov/paleo/pubs/mann2008/mann2008.html">Downloadable data set for Mann et al (2008), hosted at NOAA</a>. Includes Lake Korttajarvi primary data in file proxy-original.zip as text files tiljander_2003_darksum.ppd, tiljander_2003_lightsum.ppd, tiljander_2003_thicknessmm.ppd, and tiljander_2003_xraydenseave.ppd. Last updated Sept. 30, 2008 11:08:20 EDT<br />
<br />
<a href="http://www.climateaudit.org/data/images/mann.2008/">Graphic representations of the >1000 proxies used by Mann et al 9208)</a>, hosted at ClimateAudit.org and expressed in terms of standard deviations vs. time. Directory last updated Sept. 27, 2008. Images include proxy1061.gif (tiljander_2003_darksum), proxy1062.gif (tiljander_2003_lightsum), proxy1063.gif (tiljander_2003_thicknessmm), and proxy1064.gif (tiljander_2003_xraydenseave).<br />
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<a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/Mann-S8a-PSUwebsite-circa091104.pdf">Mann et al (2008) Fig. S8a Once-Corrected Version</a>, <i>PDF</i>, downloaded circa 3 Nov. 2009, from the Mann group's <a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxyMeans07/NHcps_no7.pdf">'Meteo' webpage</a>; <a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxyMeans07/">release notes</a>. <i>[revised 9 March 2010]</i><br />
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<a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxyMeans07/NHcps_no7_v_orig_Nov2009.pdf">Mann et al (2008) Fig. S8a Twice-Corrected Version</a>, <i>PDF</i>, downloaded circa 5 Nov. 2009 from the Mann group's webpage; <a href="http://www.meteo.psu.edu/%7Emann/supplements/MultiproxyMeans07/">release notes</a>. <i>[revised 9 March 2010]</i> <br />
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<a href="http://www.pnas.org/site/misc/iforc.shtml#viii">PNAS Information for Authors -- (viii) Materials and Data Availability</a>. "To allow others to replicate and build on work published in PNAS, authors must make materials, data, and associated protocols available to readers. Authors must disclose upon submission of the manuscript any restrictions on the availability of materials or information."<br />
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<b>The Kaufman et al (2009) Science paper and Supporting Information</b><br />
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<a href="http://www.sciencemag.org/cgi/content/abstract/325/5945/1236">DS Kaufman</a>, DP Schneider, NP McKay, CM Ammann, RS Bradley, KR Briffa, GH Miller, BL Otto-Bliesner, JT Overpeck, BM Vinther, & Arctic Lakes 2k Project Members. "Recent Warming Reverses Long-Term Arctic Cooling." Science 325:1236-1239, 2009. <i>Science web page for Abstract and Supporting Online Material, registration required for full text</i><br />
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<b>The Mann et al (2009) Science paper, Supporting Information, Comments, and Data Archive</b><br />
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<a href="http://www.sciencemag.org/cgi/content/abstract/326/5957/1256">ME Mann</a>, Z Zhang, S Rutherford, RS Bradley, MK Hughes, D Shindell, C Ammann, G Faluvegi, and F Ni. "Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly." Science 326:1256-1260, 2009. <i>Science web page for Abstract and Supporting Online Material, registration required for full text</i><br />
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<b>Hacked "Climategate" Emails Relevant to the use of the Lake Korttajarvi Proxies in Mann et al (2008)</b> <br />
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<a href="http://www.eastangliaemails.com/emails.php?eid=1011&filename=1252164302.txt">East Anglia Email 1252164302.txt</a> (also <a href="http://www.eastangliaemails.com/emails.php?eid=1010&filename=1252154659.txt">1252154659.txt</a> and <a href="http://www.blogger.com/1252154659.txt">1252154659.txt</a>). Emails sent by Nick McKay on 3 Sep. 2009 and 4 Sep 2009; responses from Darrell Kaufman and Jonathan Overpeck on 5 Sep. 2009. McKay, Kaufman, and Overpeck recognized that certain Lake Korttajarvi proxies were used upside-down in the initial published draft of Kaufman et al. (2009) (and therefore in Mann et al. (2008)). Describes process of correcting final version of paper, initiated after reading McIntyre's critiques. <i>[Entry added 27 Jun 2010]</i><br />
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<b>Analysis of Sediments from Other Scandanavian Lakes</b><br />
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Antti E.K. Ojala, "Varved Lake Sediments in Southern and Central Finland: Long Varve Chronologies as a Basis for Holocene Palaeoenvironmental Reconstructions." Academic Dissertation, Geological Survey of Finland, Espoo 2001. 41 pages. <a href="http://arkisto.gtk.fi/ej/ej41.pdf">PDF archived at the Geological Survey of Finland (GTK)</a>. Describes the collection and analysis of varved sediments at Lake Nautajärvi and Lake Valkiajärvi, with references made to four other Finnish lakes: Lake Korttajärvi, Lake Alimmainen Savijärvi, Lake Kortejärvi, and Lake Lehmilampi. AEK Ojala is the third author of Tiljander03. <i>[Added 8/3/10, hat tip to <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237548">Jarmo</a>]</i>. From page 31:<br />
<blockquote>...the recent agricultural activity [near Lake Nautajärvi] has obscured the natural signals of physical varve data, as shown by several authors earlier ([references]). According to Saarnisto (1986), small lakes respond to rapid environmental changes faster, but are more easily affected by local disturbances. Therefore, the calibration of the physical varve-data against instrumental records is, in many cases, very difficult if not impossible. The importance of multidisciplinary studies ([references]) needs to be emphasized again, because it provides a better estimate of the timing and magnitude of the effects of these cultural-related activities effect on lake sedimentation. A palaeoecological study of Lake Korttajärvi (Tiljander & Saarnisto, [MS in preparation]), for example, reported that an intensive cultivation in the vicinity of Korttajärvi began in the 16th century [<i>sic--Tiljander03 states "around 1720"--AMac</i>], as indicated by the typical culture-related pollen assemblages, L.O.I. and charcoal stratigraphy. Prior to that, fluctuations in varve composition and structure more likely reflect signals of natural origin.</blockquote><br />
M Tiljander, JA Karhu, & T Kauppila. "Holocene records of carbon and hydrogen isotope ratios of organic matter in annually laminated sediments of Lake Korttajarvi, central Finland." Journal of Paleolimnology 36: 233-243, 2006. <a href="http://www.springerlink.com/content/h020813812306288/">Abstract</a> (text behind paywall). A study of δ13C and deuterium (δD) isotopes in organic matter from 2o sediment cores retrieved from Lake Korttajarvi. The authors write that "the Medieval Warm Period (AD 980-1250) is associated with a local maximum in δD, lending support for a significant warming during that time" (<a href"http://www.co2science.org/data/mwp/studies/l2_korttajarvi.php">figure</a>).<br />
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Eeva Haltia-Hovi, Timo Saarinen, & Maaret Kukkonen. "A 2000-year record of solar forcing on varved lake sediment in eastern Finland." Quaternary Science Reviews 26: 678-689, 2007. <a href="http://www.cfa.harvard.edu/~wsoon/BinWang07-d/HaltiaHovietal07-2000yrSolarActivityEastFinland.pdf">PDF</a>.<br />
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Tomi P. Luoto, "Spatial and temporal variability in midge (Nematocera) assemblages in shallow Finnish lakes (60−70 °N): community-based modelling of past environmental change." Academic dissertation, Helsinki University, 2010. 62 pages. <a href="https://oa.doria.fi/bitstream/handle/10024/60654/spatiala.pdf?sequence=1">PDF archived at the University of Helsinki</a>. Describes analysis of fossil midges and other indicators of past climate conditions in Lake Pieni-Kauro (with some analysis and discussion of other Finnish lakes and rivers). <i>[Added 8/4/10, hat tip to <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/#comment-237696">Jarkko</a>]</i>.<br />
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Mia Tiljander, Antti E.K. Ojalaa, Timo Saarinena & Ian Snowball, "Documentation of the physical properties of annually laminated (varved) sediments at a sub-annual to decadal resolution for environmental interpretation." Quaternary International 88: 5-12, 2002. <a href="http://www.sciencedirect.com/science/article/pii/S1040618201000684">Abstract</a>. <i>[Added 8/14/11.]</i><br />
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Antti E.K. Ojala & Mia Tiljander, "Testing the fidelity of sediment chronology: comparison of varve and paleomagnetic results from Holocene lake sediments from central Finland." Quaternary Science Reviews 22: 1787-1803, 2003. <a href="http://www.sciencedirect.com/science/article/pii/S0277379103001409">Abstract</a>. <i>[Added 8/14/11.]</i><br />
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<b>Other Analyses of Varved Lakebed Sediments</b><br />
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A Brauer, GH Haug, P Dulski, DM Sigman, & JFW Negendank. "An abrupt wind shift in western Europe at the onset of the Younger Dryas cold period." Nature Geoscience 1: 520-523, 2008. <a href="http://www.glyfac.buffalo.edu/Faculty/briner/buf/pubs/Thomas_et_al_2010.pdf">PDF</a>. <i>[Added 8/25/10, hat tip to <a href="http://scienceblogs.com/stoat/2009/11/tiljander_again.php#comment-2050236">Hank Roberts</a>]</i>. The varved sediments of Lake Meerfelder Maar contain a clear record of the transition of the Holocene climate to the colder Younger Dryas regime, 12,700 BP.<br />
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EK Thomas, J Szymanski, & JP Briner. "Holocene alpine glaciation inferred from lacustrine sediments on northeastern Baffin Island, Arctic Canada." J. Quaternary Sci. 25: 146–161, 2010. <a href="http://www.glyfac.buffalo.edu/Faculty/briner/buf/pubs/Thomas_et_al_2010.pdf">PDF</a>. <i>[Added 8/25/10, hat tip to <a href="http://www.realclimate.org/index.php/archives/2010/08/doing-it-yourselves/comment-page-3/#comment-185129">Shirley Pulawski</a>]</i>. In this glacial setting, accurate and precise dating of varves isn't possible. Useful demonstration of climate-proxy information at coarser time scale, throughout the Holocene.<br />
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P.E. O'Sullivan, "Annually-laminated lake sediments and the study of Quaternary environmental changes — a review." Quaternary Science Reviews 1: 245-313, 1983. <a href="http://www.sciencedirect.com/science/article/pii/0277379183900082">Abstract</a>. <i>[Added 8/14/11.]</i><br />
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Scott Lamoureux, "Varve Chronology Techniques." Chapter 11 of <i>Developments in Paleoenvironmental Research, 2002, Volume 1, Part III</i> W.E. Last & J.P. Smol, eds. Springer, 2002, pgs 247-260. <a href="http://www.springerlink.com/content/t7354323762602p1/">Abstract</a> and <a href="http://books.google.com/books?id=p6f-W9jPXGcC&pg=PA250&lpg=PA250&dq=archive+korttajarvi&source=bl&ots=YB8DJCH5kW&sig=SC08ikQphf1YfONNSDW0rM1EzSg&hl=en&ei=xsZLTr3tBoPEgAeK4fly&sa=X&oi=book_result&ct=result&resnum=7&ved=0CDkQ6AEwBg#v=onepage&q=archive%20korttajarvi&f=false">Google Books excerpt</a>. Discussion of core-preparation techniques, with examples from Lake Korttajarvi and other Finnish lakes. Describes typical "drift" of if imputed date away from actual date in varve counts from single cores.<i>[Added 8/17/11.]</i><br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com1tag:blogger.com,1999:blog-7805174.post-33056751572138602772009-11-29T05:01:00.000-08:002011-08-14T12:11:25.160-07:00Blog Links: Mann '08 and the Korttajarvi (Tiljander) Varve Proxies<span style="font-size: 85%;">Compilation of links to blog posts and comments that address the controversy surrounding Mann et al (2008)'s use of the lakebed sediment record from Lake Korttajarvi, Finland in their reconstructions of global climate, 200 AD to 1850.<br />
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See also <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html">Primary Links: Mann '08 and the Korttajarvi (Tiljander) Varve Proxies</a><br />
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<a name='more'></a><br />
<span style="font-size: 85%;">Please add missing URLs in the comments. Since it's a compilation with little editorial content, this post may be updated without notice.<br />
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<b>ClimateAudit.org</b> ("skeptical" perspective)<br />
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<a href="http://www.climateaudit.org/?p=3536">Mann et al 2008: Korttajärvi</a>, Steve McIntyre, Sept. 3, 2008. The first claim that Mann et al used certain proxies in an upside-down orientation. Note <a href="http://www.climateaudit.org/?p=3536#comment-302197">Comment #9</a> by "varve".<br />
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<a href="http://www.climateaudit.org/?p=3951">Mann et al 2008 and GAAP Accounting</a>, Steve McIntyre, Oct. 1, 2008. Uses an accounting analogy to describe the handling of the Upside-Down Lake Korttajarvi proxies.<br />
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<a href="http://www.climateaudit.org/?p=3967">It's Saturday Night Live</a>, Steve McIntyre, Oct. 2, 2008. Detailed, illustrated explanation of the Upside-Down use of Lake Korttajarvi proxies. <a href="http://www.climateaudit.org/?p=3967#comment-304166">Comment #74</a> includes graphs of all four Lake Korttajarvi proxies.<br />
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<a href="http://www.climateaudit.org/?p=4428">Can't See the Signal For the Trees</a>, Willis Eschenbach, Nov. 23, 2008. Explains a straightforward statistical technique for combining proxies. Concludes that the longer term proxies in Mann et al (2008) are totally dominated by the Tiljander and the 19 southwestern US "stripbark" pine proxies. These proxies create the Hockeystick shape found in the signal.<br />
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<a href="http://www.climateaudit.org/?p=4501">All-Proxy CPS</a>, Steve McIntyre, Dec. 3, 2008. Emulation of Mann et al's CPS algorithm. <br />
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<a href="http://climateaudit.org/2009/04/15/more-upside-down-mann/">More Upside-Down Mann</a>, Steve McIntyre, Apr. 15, 2009 <i>[URL fixed 27 June 2010]</i> Identification of Speleo SU-967 as another proxy used in an inverted orientation in the Mann et al. (2008) paleotemperature reconstructions.<br />
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<a href="http://www.climateaudit.org/?p=7411">Upside-Side Down Mann and the "peerreviewedliterature"</a>, Steve McIntyre, Oct. 14, 2009. Good thread.<br />
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<a href="http://www.climateaudit.org/?p=7599">Connolley Endorses Upside Down Mann</a>, Steve McIntyre, Oct. 29, 2009. Good thread.<br />
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<a href="http://www.climateaudit.org/?p=7662">Another Correction from Upside Down Mann</a>, Steve McIntyre, Nov. 7, 2009<br />
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<a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/">The No-Dendro Illusion</a>, Steve McIntyre, Aug. 1, 2010. <i>[Added to list on 2 Aug. 2010.]</i> Discussion of in-line comments by Gavin Schmidt (in <a href="http://www.realclimate.org/index.php/archives/2010/07/the-montford-delusion/">"The Montford Delusion" <i>RealClimate</i> thread</a>) on the effects of using the Tiljander proxies in the paleoclimate reconstructions of Mann08 (PNAS) and Mann09 (Science). Dr. Schmidt indicated <i>en passant</i> that inclusion of the Tiljander proxies <i>does</i> matter, greatly increasing the time periods during which certain reconstructions "pass validation." That the use of the Tiljander proxies "doesn't matter" had been key to the defense of Mann08 by AGW Consensus scientists and advocates.<br />
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<a href="http://climateaudit.org/2011/06/21/amac-upside-down-mann-lives-onin-kemp-et-al-2011/">AMac: Upside Down Mann Lives on in Kemp et al 2011</a>, Steve McIntyre, June 21, 2011. <i>[Added to list on 14 Aug. 2011.]</i> <br />
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<a href="http://climateaudit.org/2011/07/06/dirty-laundry-ii-contaminated-sediments">Dirty Laundry II: Contaminated Sediments</a>, Steve McIntyre, July 6, 2011. <i>[Added to list on 14 Aug. 2011.]</i> Extensive post on the effect of inclusion of the Tiljander data series on the paleotemperature reconstructions offered in Mann08. <br />
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<b>RealClimate.org</b> ("mainstream" climate-science perspective)<br />
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<a href="http://www.realclimate.org/index.php/archives/2008/09/progress-in-millennial-reconstructions/comment-page-2/#comments">Progress in reconstructing climate in recent millennia</a>, Gavin Schmidt, Sept. 3, 2008. <i>[Added to list on 7 Mar. 2010]</i> Opening-day review of Mann et al. (2008). A good summary of what Prof. Mann's group was aspiring to accomplish. No mention of the Lake Korttajarvi proxies in the post; the issue arises in <a href="http://www.realclimate.org/index.php/archives/2008/09/progress-in-millennial-reconstructions/comment-page-2/#comment-97523">Comment #51</a> (where Dr. Schmidt dismisses their importance) and Comment 54.<br />
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<a href="http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/">RealClimate.org - Hey Ya! (mal)</a>, Group authorship, Sept. 30, 2009. Brief discussion in the Comments at <a href="http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/comment-page-14/#comment-137982">#651</a>, <a href="http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/comment-page-14/#comment-138135">#665</a>, and <a href="http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/comment-page-14/#comment-138253">#673</a>. <i>[Remarks on Comments added 27 Jun. 2010]</i><br />
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<a href="http://www.realclimate.org/?comments_popup=2019#comment-143841">RealClimate.org - Comments on the CRU Hack: Context, Comment #132</a>, Gavin Schmidt, Nov. 23, 2009. Dr. Schmidt's defense of Mann et al's handling of the Lake Korttajarvi proxies.<br />
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<a href="http://www.realclimate.org/index.php/archives/2010/07/the-montford-delusion/">The Montford Delusion</a>, Tamino, July 22, 2010. <i>[Added to list on 2 Aug. 2010]</i> Tamino's post does not discuss the Tiljander proxies. However, the subject is broached in the lengthy comment thread, and discussed by Gavin Schmidt. His in-line commentaries are at comments <a href="http://www.realclimate.org/?comments_popup=4431#comment-181898">171</a> (D. Robinson), 414 (Judith Curry), 483 (Bernie), 525 (pjclarke), 529 (Nicholas Nierenberg), and 531 (Nicholas Nierenberg). Dr. Schmidt offers important insights into the effects of using the Tiljander proxies in the paleoclimate reconstructions of Mann08 (PNAS) and Mann09 (Science), discussed at the ClimateAudit post <a href="http://climateaudit.org/2010/08/01/the-no-dendro-illusion/">The No-Dendro Illusion</a>.<br />
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<a href="http://www.realclimate.org/index.php/archives/2011/06/2000-years-of-sea-level/">2000 Years of Sea Level (+updates)</a>, Stefan Rahmstorf, 20 June 2011. <i>[Added to list on 14 Aug. 2011.]</i> <br />
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<b>Stoat</b> ("mainstream" climate-science perspective)<br />
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<a href="http://scienceblogs.com/stoat/2009/10/oh_dear_oh_dear_oh_dear_oh_dea.php">Stoat - Oh dear oh dear oh dear oh dear</a>, WM Connolley, Oct. 27, 2009. Annotated version of comment thread <a href="http://amac1.blogspot.com/2009/12/stoat-s-first-debate-on-use-of-lake.html">elsewhere on this blog</a>. <i>[Remarks added 27 Jun. 2010]</i><br />
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<a href="http://scienceblogs.com/stoat/2009/10/tiljander.php">Stoat - Tiljander</a>, WM Connolley, Oct. 29, 2009. Good thread<br />
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<a href="http://scienceblogs.com/stoat/2009/11/tiljander_again.php">Stoat - Tiljander, again</a>, WM Connolley, Nov. 4, 2009. Good thread.<br />
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<b>the Air Vent</b> ("skeptical" perspective)<br />
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<a href="">How to Make a Hockey Stick – Paleoclimatology (What they don’t want you to know)</a>, Jeff Id, Sept. 4, 2008. Discussion of generation of spurious signals by noisy proxies.<br />
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<a href="http://noconsensus.wordpress.com/2008/09/27/mann-08-temperature-reconstruction-using-less-than-11-of-the-data/#more-843">Mann 08 Temperature Reconstruction Using Less Than 11% of the Data</a>, Jeff Id, Sept. 27, 2008. Reconstruction of temperature anomaly curve of Mann et al (2008).<br />
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<a href="http://noconsensus.wordpress.com/2008/09/28/mann-08-series-weight-per-year/">Mann 08 Series Weight Per Year</a>, Jeff Id, Sept. 28, 2008. Reconstruction of Mann et al (2008) temperature anomaly graph, showing estimated weighting of Lake Korttajarvi (and other) proxies.<br />
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<a href="http://noconsensus.wordpress.com/2009/06/10/mannian-science/">Mannian Science</a>, Jeff Id, June 10, 2009. Discussion of Upside-Down orientation of temperature proxies.<br />
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<a href="http://noconsensus.wordpress.com/2009/11/05/whos-in-denial/">Who's In Denial</a>, Jeff Id, Nov. 5, 2009.<br />
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<a href="http://noconsensus.wordpress.com/2009/11/28/6858/">Mann09 Analog vs Digital</a>, Jeff Id, Nov. 28, 2009. Discussion of weighting of proxies in temperature anomaly graphs of Mann et al (Science 2009). Note <a href="http://noconsensus.wordpress.com/2009/11/28/6858/#comment-13535">Comment #15</a> on the uninformative nature of including/excluding the Lake Korttajarvi proxies from Mann et al (2008) Fig. S8a.<br />
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<b>Roger Pielke Jr.</b> ("mainstream" climate-science perspective)<br />
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<a href="http://rogerpielkejr.blogspot.com/2009/10/point-resolved-in-hockey-stick-wars.html">A Point Resolved in the Hockey Stick Wars</a>, Oct. 26, 2009.<br />
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<a href="http://rogerpielkejr.blogspot.com/2009/10/will-william-connolley-do-right-thing.html">Will William Connolley do the Right Thing?</a>, Oct. 29, 2009.<br />
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<b>Cruel Mistress</b> ("mainstream" climate-science perspective)<br />
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<a href="http://cruelmistress.wordpress.com/2009/10/26/peer-review-game-on/">Peer Review. Game on.</a> Ben Hale, Oct. 26, 2009<br />
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<b>More Grumbine Science</b> ("mainstream" climate-science perspective)<br />
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<a href="http://moregrumbinescience.blogspot.com/2009/10/sound-and-fury-at-wuwt.html">Sound and Fury at WUWT</a> Bob Grumbine, Oct. 19, 2009. Non-technically-informed defense of Mann et al's methods.<br />
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<b>Watts Up With That?</b> ("skeptical" perspective)<br />
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<a href="http://wattsupwiththat.com/2009/10/17/iq-test-which-of-these-is-not-upside-down/">IQ Test: Which of these is not upside down?</a> Antony Watts, Oct. 17, 2009<br />
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<b>Climate Progress</b> ("mainstream" climate-science perspective)<br />
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<a href="http://climateprogress.org/2008/09/03/sorry-deniers-hockey-stick-gets-longer-stronger-earth-hotter-now-than-in-past-2000-years/">Sorry deniers, hockey stick gets longer, stronger: Earth hotter now than in past 2,000 years</a>, Joe Romm, Sept. 3, 2008. <i>[Added to list on 7 Mar. 2010]</i> Favorable opening-day review of Mann et al. (2008) ("...I suspect this will be a definitive work for quite some time"). No mention of possible problems with Lake Korttajarvi proxies in post or comments.<br />
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<b>Delayed Oscillator</b> ("mainstream" climate-science perspective)<br />
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<a href="http://delayedoscillator.wordpress.com/2009/11/03/talk-about-tiljander/">Talk about Tiljander</a> Delayed Oscillator, Nov. 3, 2009. Favorable comment on <i>Stoat</i>'s discussion of Mann et al's methods.<br />
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<b>AGW Observer</b> ("mainstream" climate-science perspective)<br />
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<a href="http://agwobserver.wordpress.com/2009/11/17/papers-on-reconstructions-of-modern-temperatures/">Papers on reconstructions of modern temperatures</a>. Ari Jokimäki, Nov. 17, 2009. Compilation of papers in the same general subject area as Mann et al.<br />
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<b>Climate Observations</b> ("skeptical" perspective)<br />
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<a href="http://bobtisdale.blogspot.com/2009/12/look-at-individual-proxies-used-in.html">A Look At The Individual Proxies Used In Kaufman et al (2009)</a>. Bob Tisdale, Dec. 17, 2009. Graphical depictions of proxies used by Kaufman, including Tiljander XRD through 1800 (and multiple additional varve series).<br />
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<b>Climate Skeptic</b> ("skeptical" perspective)<br />
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<a href="http://www.climate-skeptic.com/2009/10/regression-abuse.html">Regression Abuse</a>. Warren Meyer, Oct. 29, 2009. <i>[Added to list on 28 Feb. 2010]</i> Discussion of how the Mann et al (2008) calibration strategy led to the inverted use of the Tiljander XRD proxy.<br />
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<b>Collide-a-scape</b> ("mainstream" climate-science perspective)<br />
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<a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/">The Main Hindrance to Dialogue (and Detente)</a>. Keith Kloor, Jun. 16, 2010. <i>[Added to list on 27 Jun. 2010]</i> Climate scientist and <i>RealClimate.org</i> blogger Gavin Schmidt identifies my comments on blogs (like <a href="http://www.collide-a-scape.com/2010/06/16/14/our-uncivil-climate-debate/#comment-7465">this one</a> <i>[link updated 8/2/10]</i>) as an example of a major pathology that prevents climate scientists from undertaking dialogue with critics. My responses are in the comment thread; the final one is <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/#comment-8349">#132</a> <i>[8/2/10, now <a href="http://www.collide-a-scape.com/2010/06/16/the-main-hindrance-to-dialogue-and-detente/#comment-12582">#146</a>]</i>. <br />
<br />
<b>Not Spaghetti</b> ("mainstream" climate-science perspective)<br />
<br />
The post <a href="http://arthur.shumwaysmith.com/life/content/steven_mosher_even_fuller_of_it">Steven Mosher: even Fuller of it</a> (Jun. 18, 2010) <strike>was blogger Arther Smith's criticism of author Steven Mosher's analysis of the truncation of the "Briffa reconstruction" in a figure in Chapter 6 of the IPCC AR4 report (Mosher acknowledged making the error Smith asserted). In the ensuing thread, Smith brings up possible teachings from other allegations of errors by AGW Consensus scientists. My</strike> comment <a href="http://arthur.shumwaysmith.com/life/node/93/9423#comment-9423">Tiljander/Mann fraud?</a> (06/27/2010 - 11:35) <strike>outlines my current view of the meaning and context of</strike> <i>discussed</i> the Tiljander/Mann08 case. <i>Arthur Smith elevated it to the body of his next post (below).</i> <i>[Added to list on 27 Jun. 2010; revised 7 July 2010]</i><br />
<br />
<a href="http://arthur.shumwaysmith.com/life/content/wheres_the_fraud">Where's the fraud?</a>. Arthur Smith, June 27, 2010. <i>[Added to list on 7 July 2010]</i> Arthur Smith reviews the AGW Consensus stance on the use of the Tiljander proxies (and other issues with Mann08), Part 1. Good discussion in the comments.<br />
<br />
<a href="http://arthur.shumwaysmith.com/life/content/michael_manns_errors">Michael Mann's errors</a>. Arthur Smith, June 30, 2010. <i>[Added to list on 7 July 2010]</i> Arthur Smith reviews the AGW Consensus stance on the use of the Tiljander proxies (and other issues with Mann08), Part 2. Good discussion in the comments.<br />
<br />
<b>AGW Observer</b> ("mainstream" climate-science perspective)<br />
<br />
<a href="http://agwobserver.wordpress.com/2010/06/28/tiljander/">Tiljander</a>. Ari Jokimäki, June 28, 2010. <i>[Added to list on 7 July 2010]</i> Ari Jokimäki considers revising his support of the AGW Consensus stance on the X-Ray Density proxy, first outlined in the comments at <i>Stoat</i>. Good discussion in the comments.<br />
<br />
<b>Our Changing Climate</b> ("mainstream" climate-science perspective)<br />
<br />
<a href="http://ourchangingclimate.wordpress.com/2011/06/22/climate-science-scientific-method-skeptics-not/">How science does and does not work (and how skeptics mostly fall in the latter category)</a>. Bart Verheggen, June 22, 2011. <i>[Added to list on 14 August 2011.]</i> The Tiljander data series are first mentioned in <a href="http://ourchangingclimate.wordpress.com/2011/06/22/climate-science-scientific-method-skeptics-not/#comment-13420">this comment by MikeN</a>. Involved discussions of the subject follow.<br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com6tag:blogger.com,1999:blog-7805174.post-48454618597114129062009-11-28T07:30:00.000-08:002010-03-10T22:05:29.562-08:00The Newly-Discovered Jarvykortta Proxy: Relevant to the Tiljander Varve Series?<span style="font-size: 85%;"><b>[Update 9 March 2010 -- I've rewritten "The Newly-Discovered JarvyKortta Proxy" making its points clearer and adding some graphs. What follows on this page is for completeness' sake.<br />
<br />
The updated post is <a href="http://amac1.blogspot.com/2010/03/newly-discovered-jarvykortta-proxy-ii.html">here</a>.]</b><br />
</span><br />
<a name='more'></a><br />
<span style="font-size: 85%;">The <i>Climate Audit</i> post <a href="http://www.climateaudit.org/?p=7855">Yet Another Upside Down Mann out</a> caused me to write the following remarks about the use of the Lake Korttajarvi, Finland varve proxies in paleoclimate reconstructions.<br />
<br />
My generous use of embedded URLs seems to have routed the comment into Spam Purgatory. Despite liberal purchases of Indulgences, it remains there to this day. So, here it is as a blog post.<br />
<br />
<b>Update 27 Feb 2010</b> -- <i>This post assumes the existance of a fictional monastery alongside a fictional "Jarvykortta River" (cf. the real Lake Korttajarvi) in fictional Ruritania (cf. Finland). The point is to explore whether a proxy series can be inadvertantly used in an upside-down orientation. I use this example to illustrate that Yes, such an error is quite possible. I argue that a data series refers back to a characteristic that must only be used in the orientation that makes logical sense with respect to what it represents in the physical world.</i><br />
<br />
I recently returned from a trip to <a href="http://en.wikipedia.org/wiki/Ruritania">Ruritania</a>. While there, I met with the Abbott of the Jarvykortta Monastery, who told me that the monks have kept a continuous record of the ice breakup date of the adjacent Jarvykortta River since before 400 AD.<br />
<br />
It struck me that this could be <a href="http://www.john-daly.com/nenana.htm">a useful proxy</a> for the Northern Hemisphere Temperature Anomaly, so I asked if I might have access to these records, and any other information the monastery might have. The Abbott graciously agreed.<br />
<br />
The year-by-year record, 389 - 1985 is <a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/">at BitBucket</a>, as Excel file <a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/Jarvykortta-Ice-Out-Proxy.xls"> Jarvykortta-Ice-Out-Proxy.xls</a>.<br />
<br />
The date of the Jarvykortta River breakup has been as early as February 15 (in 1231) and as late as June 20 (in 1967). For graphing purposes, I have taken the 11-year rolling average of this series, much as Tiljander et al (2003) did for their varve X-Ray Density data from Lake Korttajarvi, Finland.<br />
<br />
I should stress that it was the Finnish <i>Lake Korttajarvi</i> XRD series (Column C in the Excel file) and <b>not</b> this newly-discovered Ruritanian <i>Jarvykortta River</i> series (Column D) that was used by Mann et al (PNAS, 2008) and now, apparently, by Mann et al (Science, 2009).<br />
<br />
As with many proxies, there are some potential complications. The Abbott related the following three points to me:<br />
<ol><li>There is a natural hot spring that empties into the Jarvykortta River, about 1 kilometer upstream of the Monastery. Its flow appears relatively constant, year-to-year. This addition of hot water would make the ice on the river break up earlier than would otherwise be the case.<br />
</li>
<li>Around 1720, a few local farmers began piping some of the hot spring's output to their homes. As the population of the area grew in the 18th and 19th Centuries, this practice became more widespread. This likely led to increasing delays in the timing of the Spring breakup of the river ice by the monastery.<br />
</li>
<li>For much of the 20th Century, the nearby town maintained a skating rink for the winter and spring, just upstream of the monastery. Cooling coils were placed in the river to keep the rink ice solid, well into the spring. In the late 1920s/early 1930s, and again in 1967, hockey playoffs went into late May.<br />
</li>
</ol>Also at BitBucket, I have placed an chart that displays this Jarvykortta River proxy (green line) and the Mann et al (2008) Northern Hemisphere CPS Temperature Anomaly (red line). This JPEG file can be downloaded as <a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/Jarvykortta-Ice-Out-Proxy.jpg"> Jarvykortta-Ice-Out-Proxy.jpg</a><br />
<br />
It is difficult to determine how the Ice-Out signal should be related to regional warming or cooling. The Abbott suggested that earlier thaws might generally correlate with milder winters, while late thaws could be due to harsh winters--aside from human effects.<br />
<br />
However, a computer program that interpreted rising numbers from 1850 to the present as a signal of regional warming would orient the Ice-Out signal such that earlier ice breakups are correlated with <i>colder</i> temperatures.<br />
<br />
Since reliance on complex algorithms is a hallmark of sound experimental practices, I have oriented the Ice-Out proxy in the latter fashion.<br />
<br />
The pattern that results is certainly interesting.<br />
<br />
I hope this contribution of a novel data series proves helpful in interpreting the Lake Korttajarvi X-Ray Density varve record that was assembled by Tiljander and her colleagues.<br />
<br />
It is possible that the two proxies share certain features, as summarized in the one-page summary chart <a href="http://bitbucket.org/amac/tiljander-proxy-graphs/downloads/Jarvykortta+Korttajarvi-Proxies.pdf">Jarvykortta+Korttajarvi-Proxies.pdf</a> at BitBucket.<br />
<br />
<b>UPDATE 2</b> -- Here's that PDF'd chart at BitBucket as an html table.<br />
<br />
<table align="center" border="1" cellpadding="1" cellspacing="0"><tbody>
<tr><td><b>Series</b></td><td><b>Lake Korttajarvi Varve XRD</b></td><td><b>Jarvykortta River Ice Breakup</b></td></tr>
<tr><td>Characteristic</td><td>X-Ray Densities of Lakebed Sediments</td><td>Date of Ice Breakup of River</td></tr>
<tr><td>Source</td><td>Tiljander et al (2003)</td><td>Monastary Abbott</td></tr>
<tr><td>Dates</td><td>389-1985**</td><td>389-1985**</td></tr>
<tr><td>Low value</td><td>1231: 46 (greyscale)</td><td>1231: Feb 15 (46th day of year)</td></tr>
<tr><td>High value</td><td>1967: 172 (greyscale)</td><td>1967: Jun 20 (172nd day of year)</td></tr>
<tr><td>Influence of temperature on series?</td><td>Yes</td><td>Yes</td></tr>
<tr><td>Source’s interpretation of temp. effects</td><td>Harsher winters lead to mineral-rich varves and higher XRDs</td><td>Harsher winters lead to later date of ice breakup</td></tr>
<tr><td>Non-temperature natural influences on series?</td><td>Yes</td><td>Yes</td></tr>
<tr><td>Source’s interpretation of non-temp. influences</td><td>Higher precipitation increases XRD value</td><td><i>Lesser flow of</i>* hot springs upriver increases date of ice breakup</td></tr>
<tr><td>Human influences?</td><td>Yes</td><td>Yes</td></tr>
<tr><td>Source’s interpretation of human influences</td><td>1720 on, farming increased <br />
sedimentation and XRD values</td><td>1720 on, diversion of hot springs increased ice breakup dates</td></tr>
<tr><td>Known artifacts</td><td>Late 1920s: Peat cutting increased XRDs<br />
1967: Bridge reconstruction increased XRD</td><td>Late 1920s: Skating rink increased ice breakup date<br />
1967: Hockey final increased ice breakup date</td></tr>
<tr><td>Source’s summary</td><td>Higher XRDs mean lower temps, unreliable post-1720</td><td>Later ice breakups mean lower temps, unreliable post-1720</td></tr>
<tr><td>Mann et al (2008) <br />
interpretation</td><td>Computer screening algorithm <br />
1850-1995 shows that higher XRDs <br />
must mean higher temps</td><td>n/a</td></tr>
<tr><td>Common sense interpretation</td><td>Higher XRDs mean lower temps. Unreliable post-1720</td><td>Later ice breakups mean lower temps. Unreliable post-1720</td></tr>
</tbody></table><br />
* <i>Lesser flow</i> added as clarification.<br />
** 12/23/09 -- Typo fixed; "1389" to "389".<br />
<br />
<b>UPDATE</b> -- The Ruritanian "Jarvykortti River" proxy that I concocted is comprised of a set of numbers that is <i>identical</i> to the actual set of Lake Korttajarvi varve X-Ray Density greyscale values that Mia Tiljander reported in the course of her graduate studies in Finland.<br />
<br />
For instance, the X-Ray Density of the varve that was deposited in 1220 was 54. So, in 1220, I had the ice on the Jarvykortta River break up on February 23--the 54th day of the year. In the decade of the 1220s, the ice broke up as early as Feb. 17 (1229), and as late as Feb. 28 (1225).<br />
<br />
By contrast, when 170 years had passed, the ice in front of the mythical Jarvykortti Monsastery broke up about 5 weeks later in the season. For the 1390s, the earliest year of the ice breakup was 1395 (March 20), while the latest was 1391 (April 15).<br />
<br />
Of course, all of these "ice-breakup dates" are nothing other than the Lake Korttajarvi varve greyscale values, translated by Excel into days-of-the-year.<br />
<br />
At first, it sounds plausible when defenders of the Upside-Down usage of the Lake Korttajarvi varve proxies claim that "The higher the varve XRD, the warmer the average temperature has been." After all, who goes through the day thinking about varve densities?<br />
<br />
But! This assertion about varves maps directly to the claim that "The later in the season that the river ice breaks up, the warmer the average temperature has been."<br />
<br />
Everybody knows that when the winter is warm, ice breaks up <i>early</i>--not late!<br />
<br />
Winters at the Jarvykortta Monastery had surely been warmer in the 1220s than they were in the 1390s.<br />
<br />
The <i>identical logic</i> lets us know what Mia Tiljander's varve data is telling us about the climate of Lake Korttajarvi in central Finland. It was warmer in the 1220s than it was in the 1390s.<br />
<br />
Mann et al's trust in their statistical algorithms have fooled them into thinking that the 1220s <i>must</i> have been cooler than the 1390s.<br />
<br />
But the Tiljander proxies are clear: Mann and his colleagues are wrong.<br />
<br />
Don't manipulate the data to fit the theory--that's backwards!<br />
<br />
<b>[Update 9 March 2010 -- these comments are closed; go <a href="http://amac1.blogspot.com/2010/03/newly-discovered-jarvykortta-proxy-ii.html">here</a> instead.]</b><br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com3tag:blogger.com,1999:blog-7805174.post-81866973539044499772009-11-28T05:33:00.000-08:002009-12-04T11:22:07.918-08:00Norman Wolmark's Perspective on the History of Breast Cancer Therapy<span style="font-size: 85%;">Dr. Wolmark gave a brief talk on this subject at an autumn 2009 conference sponsored by the diagnostic company <a href="http://investor.genomichealth.com/">Genomic Health</a>. It was a real eye-opener, on the messy, lurching nature of <i>progress</i> at the intersection of Science and Art that defines clinical practice.<br />
<br />
In a broader sense, the themes discussed here are important whenever the results of Scientific Inquiry have important impacts in the wider world. Policy decisions are the result of <i>political</i> contests; the application of scientific insights will be only a modest ingredient for this recipe.</span><br />
<a name='more'></a><br />
<span style="font-size: 85%;">Norman Wolmark MD practices at Allegheny General Hospital in Pittsburgh, where he is the <a href="http://www.wpahs.org/patients/physician/index.cfm?mode=Bio&physician=1595">Chairman of the Department of Human Oncology</a>. His credentials also include Professor of Human Oncology at the Drexel University College of Medicine. He has gained the most renown for his leadership role with the long-running <a href="http://www.nsabp.pitt.edu/BCPT_Speakers_Biographies.asp">National Surgical Adjuvant Breast and Bowel Project</a> (NSABP) -- the focus of this talk.<br />
<br />
The following text was transcribed from <a href="http://www.talkpoint.com/viewer/starthere.asp?Pres=128458">the audio recording</a> (registration required) of Genomic Health's Analyst Day, held on the afternoon of November 12, 2009 in Manhattan. It begins at about the 1 hour, 14 minute mark, and runs to about 1:29:00.<br />
<br />
To my knowledge, these remarks are otherwise unpublished. Dr. Wolmark gave a Grand Rounds presentation at the NIH Clinical Center on Sept. 9, 2009 touching on some of these themes; that is <a href="http://pop.cc.nih.gov/podcast/transcripts/2009/CCGR_2009-021.html">Episode 2009-021</a>.<br />
<br />
<b>Dr Wolmark's lecture</b> (links added, minimal editorial cleanup) --<br />
<blockquote>The main advancement relative to changing the state of the art has been the ascent of the randomized prospective clinical trial. This represented the clinician’s opportunity to advance the state of the art using the scientific method, in an unbiased, disinterested, totally objective fashion. It was in fact the clinician’s laboratory.<br />
<br />
It was a method that was to deliver us from the age of tyranny, the age of authoritarianism, when an individual could ascend to the professorial pulpit and -- armed with a retrospective anecdotal case series, based on his personal charisma, or the prestige of the institution that he represented -- could virtually dictate the standard of care for generations to come.<br />
<br />
You think that this is a parable that I’m telling you about? It isn’t! This is how the standard of care for breast cancer was evolved!<br />
<br />
<a href="http://en.wikipedia.org/wiki/William_Stewart_Halsted">William Stewart Halsted</a> in 1895 popularized the radical mastectomy. A <i>mutilating</i> operation that removed the breast, and the underlying muscles, and the lymph nodes, <i>en bloc</i>: based on his biological perception of the disease. He viewed breast cancer as a disease that disseminated in a local-regional fashion, by tentacles, connected to the primary tumor. So, if he saw a patient with a liver metastasis, according to this hypothesis, that metastasis arrived at the liver by direct extension, connected to the primary tumor. So it was perfectly logical for Halsted to have evolved a mutilating operation, removing muscles because muscles were covered by fascia, and the fascia was the conduit of spread. <i>The evil fascia</i>.<br />
<br />
We’re still infatuated with it today! Our basic operations for many solid tumors are based on that biologic perception of the disease.<br />
<br />
It’s interesting that in 1898, William Stewart Halsted stood up to address the august American Surgical Association. He thanked them for embracing his operation, and his biological perspectives. And we can only conclude that he either was asleep or he was out of the room. Because following his presentation, there was an individual, <a href="http://en.wikipedia.org/wiki/Rudolph_Matas">Rudolph Matas</a> of New Orleans, who stood up.<br />
<br />
Dr. Matas said that it is not the number of local recurrences, but the number of <i>cures</i> that should be used as a metric for the value of an operative procedure. He understood that patients were not dying because of inattention to operative detail. They were dying because they already had micrometastatic disease at the time of the operation!<br />
<br />
He said that the words used to describe the operation as "radical" or complete -- radical from the Latin "radic," the root -- in the sense that they root out all the evil -- was illusory and inappropriate.<br />
<br />
And, of course, his commentary never got published! He was purged from the historical annals of breast cancer! The voice from Johns Hopkins Hospital was far more persuasive, far more pervasive, far more authoritative, than that solitary whisper from Tulane.<br />
<br />
1898. Two mutually exclusive hypotheses. The scalpel versus the hypodermic needle. Therapy based on empiricism versus therapy based on molecular markers.<br />
<br />
We think we have made great advancements? These two hypotheses were proposed <i>in 1898</i>. And they were suppressed.<br />
<br />
It wasn’t until 1971 that these two hypotheses were resurrected. It was done by Bernie Fisher, who deserves a great deal of credit. He had the courage to resurrect these hypotheses, not as an exercise, but to test them using the scientific method -- using the randomized prospective clinical trial.<br />
<br />
It was in 1971 that we started the "BO era" [of the NSABP] with the BO-4 trial, which compared the radical mastectomy to a heretical, lesser operation, where the lymph nodes were left behind.<br />
<br />
That led to the next step in the retreat from radical mastectomy, the BO-6 trial. It was started in 1976, mastectomy versus preserving the breast, to test these two mutually exclusive hypotheses. And the survival for the lesser procedures was identical to the radical mastectomy!<br />
<br />
This wasn’t simply an issue of doing breast-preserving operations. It had enormous biological implications. Because if one accepted the lesser operative procedure, one had to <i>change one’s biological perspective of the disease</i>!<br />
<br />
The outcomes of these trials convinced surgeons of the modern era, once and for all, that it was <i>not</i> operative nuances that explained the differences in survival. If we were going to make gains in the cure rate for breast cancer and other solid tumors, we would have to address the systemic component of the disease: the micrometastases that were already extant at the time that patient was treated in the operating room.<br />
<br />
This led to the first trial using <a href="http://www.cancer.gov/cancertopics/factsheet/Therapy/adjuvant-breast">adjuvant therapy</a>, which was started in 1972. We used two years of oral LPAM [L-phenylalanine mustard], and showed a statistically significant advantage. This supported the alternate hypothesis.<br />
<br />
And so, with the retreat from radical mastectomy, we had the ascent of systemic therapy. The two are inextricably intertwined, because they are one and the same part of the alternate hypothesis. That opened the floodgates for a series of adjuvant therapy trials that followed. CMF [cyclophosphamide, methotrexate and fluorouracil] supplanted LPAM in 1976. In the seventies, we went on to address the value of adding tamoxifen for Estrogen-Receptor-positive patients in study NSABP B-09. We published those results in 1981.<br />
<br />
In the 1980s, we introduced anthracyclines into the adjuvant setting. In the 90s, taxane. In the past decade, we have worked on "variations on a theme" with taxane. Dose-dense therapy? Do we give agents in combination? Should we give them sequentially? And currently, we are reassessing the value of anthracycline.<br />
<br />
Until now, I have been avoiding the basic paradigmatic question. Have we crossed the elusive threshold between <i>therapy based on empiricism</i> and <i>therapy based on molecular discriminants</i>?<br />
<br />
The answer is that we have.<br />
<br />
The years between 2003 and 2005 were pivotal. The first example was NSABP protocol B-31, where we studied node-positive breast cancer patients whose tumors overexpressed or amplified the <a href="http://en.wikipedia.org/wiki/HER2/neu">HER2/neu</a> gene. [We investigated the use of the drug <a href="http://en.wikipedia.org/wiki/Trastuzumab">Herceptin</a>, which blocks the cancer-promoting activity of the her2neu gene]. We started that trial in 2000.<br />
<br />
[snip]<br />
<br />
And at the first interim analysis, when we combined that data with North-Central 9831, there was that magic, fleeting moment of Eureka! We saw enormous differences--absolute differences of 18% in favor of <i>Herceptin</i>! [For the first time, targeting a specific molecular discriminant worked.] We had a P value [for statistical significance] that had 11 zeroes after the decimal place! We submitted our report of this clinical trial to the <i>New England Journal of Medicine</i>.<br />
<br />
They said, "You can’t put 11 zeroes after the decimal place. Our policy only allows you to put three zeros after the decimal place."<br />
<br />
We said, "Why?"<br />
<br />
They said, "That’s our policy."<br />
<br />
We said, "How many have you seen like this?"<br />
<br />
They said, "We’ve never seen one."<br />
<br />
But--of course--their policy prevailed. Why? Because they are authoritarian.<br />
<br />
So that is proof of principal.<br />
<br />
[snip]<br />
<br />
The <i>Oncotype DX</i> [Genomic Health's molecular diagnostic test for breast cancer] was developed in a meticulous, obsessive manner. And it was validated in an appropriate and blinded manner, where the link between the outcome and the data set existed with one honest broker. This broker was the only link between the data and the outcome parameters.<br />
<br />
The beauty of the <i>Oncotype DX</i> -- aside from the fact that it gives you unblinded information -- is that it is practical.<br />
<br />
[snip]</blockquote><b>UPDATE</b> 12/4/09 -- Dr. Wolmark caught a couple of spelling errors; corrected.<br />
</span>AMachttp://www.blogger.com/profile/08872008617279528583noreply@blogger.com1