bender drew our attention to the following interesting paper from Evans et al (including Heghes and Vaganov) attempting the salutory exercise of forward modeling tree ring site chronologies from climate data. bender quoted from the intro: Two major uncertainties lie in the statistical development, analysis and interpretation of tree-ring data for paleoclimate studies. First, there […]
(2012 Update…) CA was the first blog to discuss the recent papers by Wilmking and his associates on “positive and negative responders” – the opposite response of trees to recent warming in which – at the same site – some trees responded positively and some negatively. This is an important observation in trying to provide […]
The 2000 conference of the IAI project on “Reconstructing Climate Variability and Change from Treelines” contained the following abstract describing a network of high-elevation “temperature-sensitive” tree ring chronologies as follows: 6. An expanded network of long treeline chronologies from the Western US Brown, P.M.; Woodhouse, C.A. & Hughes, M.K. We report on new, high elevation, […]
In 1999, the IAI launched a major initiative entitled Assessment of Present, Past and Future Climate Variability in the Americas from Treeline Environments . They state: “The overarching scientific goal of this project was to reconstruct climate variability over a major global transect from Alaska to Tierra del Fuego.” While Mann has told us that […]
Dendroclimatologists have told us that they want to root out misinformation like anyone thinking that white spruce chronologies from northern Alberta archived at the ITRDB are temperature proxies. I’ve conveyed that message to CA readers and I’m happy to report that, as far as I know, CA readers agree that northern Alberta white spruce chronologies […]
Over at the Dendro listserv, Rob Wilson raised the issue of what dendros should do about climateaudit, noting that he felt a responsibility to “defend dendro practises and correct misinformation.” He went on to say: Although some of the criticisms and commentary are valid, some of it is simply wrong and misinformed, and in my […]
While I was reading about rotated varimax PCA in connection with Rob Wilson’s article, I came across R.W. Houghton and Y.M. Tourre, 1992, Characteristics of Low-Frequency Sea Surface Temperature Fluctuations in the Tropical Atlantic, Journal of Climate Volume 5, Issue 7 (July 1992) pp. 765—772 url. They observed that a PC analysis applied to Atlantic […]
Rob Wilson has referred us to Wilson et al 2007. In addition to being an example of site selection, Wilson et al 2007 uses a type of principal components on a tree ring network – something that should be of interest to many CA readers – and an interesting illustration of non-Mannian statistical methods within […]
A couple of days ago, I canvassed the ITRDB data bank for all tree ring series with values later than 1998, noting that there were many new series. Mann has justified the reliance on proxies not updated since 1980 and earlier, and thus not calibrated against recent warmth, on the basis that it is very […]
Two respected dendrochronologists wrote in criticizing my recent post averaging new white spruce chronology contributions to the ITRDB data bank. [Update: see post here with further thoughts on the location of this site. Next post in category] Rob Wilson wrote, using an uncharacteristic Gavin-esque sigh, as follows:
Climate Audit 