Category Archives: Noamer Treeline

Climate Variability in the Americas from Treeline Environments

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 […]

The Dendroclimatologists are Angry

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 […]

Varimax Rotation and the AMM

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 […]

Wilson et al 2007

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 […]

Latitudinal Treeline

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 […]

Wilson, Pisaric and Gaspé

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:

Up-to-Date White Spruce Ring Widths

“Bring the proxies up to date” was the title of one of my earliest posts. Michael Mann had explained that doing so required the use of heavy equipment (like tree ring borers) and travel to out-of-the way sites such as Bishop, California or even Niwot Ridge, a full 45 minute drive from UCAR world headquarters […]

Alberta #3

In February 2006, Luckman and Wilson archived their STD chronology for the Athabasca Glacier, Alberta site (STD fits each tree individually; RCS fits trees in groups.) Rob Wilson wrote in criticizing an earlier post for, among other things, not showing their STD version and for how I implemented the RCS emulation for Esper et al […]

Alberta #2

There are 3 different versions of the Alberta site that have been applied in multiproxy reconstructions: 1) Luckman et al [1997] used in Jones et al [1998]; Crowley and Lowery [2000]; Briffa [2000]; 2) Esper et al. [2002] ; 3) the version used in Osborn and Briffa [2006], presumably from Luckman and Wilson [2005] and […]

The Alberta Site in Esper 2002

Here is some more analysis based on the Esper measurement data sent to me by Science on March 16, 2005 — this time on the “Athabasca” site, which refers to a location in the Rocky Mountains, Alberta near the Athabasca Glacier. This note is rather a status report, so that I keep track of what […]