Kaufman et al (2009), published at 2 pm today, is a multiproxy study involving the following regular Team authors: Bradley, Briffa (the AR4 millennial reconstruction lead author), Overpeck, Caspar Ammann, David Schneider (of Steig et al 2009), Bradley as well as Otto-Bleisner (Ammann’s supervisor and conflicted NAS Panel member) and “JOPL-SI authors” who are various contributors of sediment series.
One of the few proxy data contributors not listed as a coauthor is Mia Tiljander, whose data was used upside down in Mann et al 2008. Amusingly, the Kaufman Team perpetuates Mann’s upside down use of the Tiljander proxy, though they at least truncate the huge blade (resuling from modern sediments from bridge-building and farming.)
The graph below shows the original data from Tiljander (oriented so that warm is up.)
Figure 1. Excerpt from Tiljander Boreas 2003 Figure 5 – rotated to warm is up orientation. The increased sedimentation in 19th and 20th centuries is attributed to farming and bridge construction and is not evidence of “cold”.
Mann et al 2008 series #1064 can be seen to be an inverted version of the Tiljander series, as shown by the plot below.
Kaufman et al make decadal averages of their proxies. The graph below shows the Mann 2008 data (Mann orientation), converted to 10 year anomalies, truncated to 1800 and then scaled. Mann orientation is upside-down to the orientation in Figures 1 and 2.
Next here is a plot of Kaufman series #20 (lake Kortajarvi) from their SI. This was presented in an exceedingly annoying format – it was available only in a photo form and thus the data was not available digitally. I transcribed series 20 manually and may have a couple of discrepancies as the data format was very annoying. (I’ve uploaded my transcription) In addition, data was missing in the SI from 1225 to 1105. Unlike Mann et al 2008, Kaufman et al truncated post-1800 data. You can readily see that this closely matches the Mann version and is thus also upside-down relative to Tiljander’s intended orientation.
The continued use of upside-down data by the Team is really quite remarkable. It’s not as though they were unaware of the issue.
The upside-down use of Tiljander data was originally observed at CA http://www.climateaudit.org/?p=3967). We know that Mann and Schmidt were monitoring CA because changes to Mann’s SI (always without attribution) were made soon after CA posts.
The use of upside-down data in MAnn et al 2008 was even published at PNAS earlier this year (McIntyre and McKitrick PNAS 2009 see here). In their response at PNAS, Mann et al described the claim that they used the data upside-down as “bizarre”, notwithstanding the fact that the correctness of the observation could be readily seen merely by plotting Mann’s data (and even in the data plots in the Mann et al 2008 SI).
The Team is exceptionally stubborn about admitting even the least error. We had seen an amusing illustration in Mann et al 2007, where the incorrect geographic locations of MBH98 proxies was perpetuated: the rain in Maine still continued to fall mainly in the Seine.
It is even more amusingly illustrated by Kaufman’s perpetuation of Mann’s upside down use of the Tiljander proxy (rather than conceding Mann’s error and using the data in the right orientation.) Also note here that Bradley was involved in both studies.
I’m sure we’ll soon hear that this error doesn’t “matter”. Team errors never seem to. And y’know, it’s probably correct that it doesn’t “matter” whether the truncated Tiljander (and probably a number of other series) are used upside-down or not. The fact that such errors don’t “matter” surely says something not only about the quality of workmanship but of the methodology itself.
[Update Sep 8] – Last week, I notified Kaufman about the use of Upside Down Tiljander, asking in addition for various “publicly available” data sets that do not appear to actually be available anywhere that I know of. He replied yesterday attaching a graph indicating that it doesn’t matter whether Tiljander is used upside down and unresponsively referred me to the decadal values of the data already available.
What does “matter” in these sorts of studies are a few HS-shaped series. Testing MBH without the Graybill bristlecones provoked screams of outrage – these obviously “mattered”. Indeed, in MBH, nothing else much “mattered”. The Yamal HS-shaped series (substituted in Briffa 2000 for the Polar Urals update which had a high MWP) plays a similar role in the few studies that don’t use Graybill bristlecones. The present study doesn’t use bristlecones, but Briffa’s Yamal substitution is predictably on hand. (See the latter part of my 2008 Erice presentation for some discussion of this.)
Further analysis will require examination of the individual proxies. Kaufman et al provide 10-year decadal averages in their photo SI, promising that data will be made available at NCDC, but it wasn’t as at the time of writing this note. While they say that all data is public (other than annual versions of some series that they obtained from original authors), but I could only locate digital versions of some of the series.
The problem with these sorts of studies is that no class of proxy (tree ring, ice core isotopes) is unambiguously correlated to temperature and, over and over again, authors pick proxies that confirm their bias and discard proxies that do not. This problem is exacerbated by author pre-knowledge of what individual proxies look like, leading to biased selection of certain proxies over and over again into these sorts of studies.
We’ve seen this sort of problem with the Yamal tree ring series (22), which has been discussed at CA on many occasions. (See for example the discussion in the latter part of http://climateaudit.files.wordpress.com/2008/09/mcintyre.2008.erice.pdf ). Briffa originally used the Polar Urals site to represent this region and this data set was used in MBH98-99 and Jones et al 1998. This data set was updated in the late 1990s, resulting in an elevated Medieval Warm Period. Briffa did not report on the updated data; it has never been reported. The data only became available after quasi-litigation with Science in connection with data used in Esper et al 2002. Instead of using the updated Polar Urals version with an elevated MWP, Briffa constructed his own chronology for Yamal, yielding a hockey-stick shaped result. The Yamal substitution has been used in virtually every subsequent study (a point noted by Wegman et al 2006) and is used once again in Kaufman et al 2009. In other studies, a simple replacement of the Yamal version with the updated Polar Urals version impacts the medieval-modern relationship and this needs to be considered here.
On the other hand, a long Siberian tree ring series known to have an elevated MWP is not used: the Indigirka River (Siberia) tree ring series was used in Moberg et al 2005, but is not used in this study, though it is a long chronology in the same sort of region.
They use Briffa’s version of Tornetrask (as a leading component of their Fennoscandia (#18). Tornetrask is used in virtually every reconstruction, a point made on many occasions at CA (also see Wegman et al 2006). An updated Tornetrask version (Grudd 2008) had an elevated medieval warm period – see discussion in http://climateaudit.files.wordpress.com/2008/09/mcintyre.2008.erice.pdf).
Notable omissions are the Mount Logan ice core and Jellowbean Lake sediment series. (See http://www.climateaudit.org/?p=2348, http://www.climateaudit.org/?p=806 for discussion of the Mount Logan proxies.) The Mount Logan ice core delO18 values decrease in the 20th century, contrary to the presumed increase. Although Mount Logan isotopes are as well resolved as the ice core isotopes used by Kaufman et al, they are excluded (along with a candidate sediment series) on the basis that the “bad” results for these proxies are due to changes in “moisture source” rather than temperature.
We excluded the isotope-based records from ices cores in the Saint Elias Mountains (S4) and from Jellybean Lake carbonate (S5), both in the Yukon, because the proxies are more strongly controlled by changes in moisture-source and atmospheric moisture transport patterns than by temperature.
The problem with this sort of reasoning is: if changes in moisture source cause isotope values to go down, they will also cause isotope values to go up.
Worsening this particular situation is the failure of Lonnie Thompson to report “adverse” results at Bona-Churchill (see the CA posts mentioned above.) Bona-Churchill, an ice core site near Mount Logan, was drilled in 2002. The unseemly delay in reporting results led me to speculate several years ago that these results were “bad” for Lonnie Thompson’s advocacy. This prediction was confirmed in a diagram presented in a workshop; the data itself remains unpublished to this day.
I note that the Dye-3 isotopes (#12) have been “corrected” to account for ice flow. In my opinion, the place for such adjustments should be in the original articles and not in multiproxy compilations. This will need to be assessed.
As has observed on many occasions at CA and on other critical blogs (it’s been independently noted by Jeff Id, David Stockwell and Lubos Motl as well as myself), when data sets are selected ex post according to whether they go up in the 20th century – as opposed to all the data sets, the results are subject to a very severe HS bias. David Stockwell published this result in 2006 (see here) (an article cited in McIntyre and McKitrick PNAS 2009) illustrating it as below (similar illustrations are available at Jeff Id’s and Luboš’):
The most cursory examination of Kaufman et al shows the usual problem of picking proxies ex post: e.g. the exclusion of the Mount Logan ice core and Jellybean Lake sediment series; or the selection of Yamal rather than Polar Urals – a problem that is even pernicious because of the failure to archive “bad” results (e.g. Thompson’s Bona-Churchill or Jacoby’s “we’re paid to tell a story”). Until these problems are rooted out, it’s hard to place much weight on any HS reconstruction.
Update: Here are interesting layers extracted from Kaufman showing the respective contributions of the respective proxy types clearly rather than the typical spaghetti graph. This shows nicely that the seven (of 23) ice core proxies make no contribution to the HS-ness of the result and that they do not show 20th century uniqueness. The biggest HS comes from the Briffa tree rings (and I’m sure that the Yamal series will contribute the majority of the HS-ness in this composite.) The 12 sediment series are intermediate: here we still need to examine the orientation of these series and which sediment series contribute to HS-ness.
Update: As noted by a reader in the Loso thread, compaction is a problem with this sort of data. The Murray Lake data includes density information, which is plotted below. Density stabilizes at a mean of about 1.09, but less compacted recent sediments are less dense.
Reference: Kaufman et al Science 2009. SI Data is supposed to be at http://www.ncdc.noaa.gov/paleo/pubs/kaufman2009 but isn’t there as at Sep 3, 2009 6 pm when the article was published.
Tiljander, Boreas 2003 http://climateaudit.files.wordpress.com/2009/09/tiljanderetal.pdf