The tree ring dataset for the critical Polar Urals site has gaps of up to 59 years, has cores with as many 7 breaks in them. The problems are so pervasive that COFECHA testing simply fails – an almost unprecented occurrence in a tree ring data set.
The Polar Urals site is a staple of multi-proxy studies. The Briffa et al. [1995] version is used in Jones et al [1998], MBH98, MBH99, Briffa et al. [2001] and most recently Jones and Mann (2004). An earlier version by Graybill and Shiyatov was used in Bradley and Jones [1993], Hughes and Diaz [1994] and […]
In most "long" presentations of climate change in the IPCC framework, we see Vostok ice core going back to about 800 Kyr, covering most of the Pleistocene. What easily gets lost sight of in this format is just how unusual the Pleistocene itself is. It is one of only a few glaciations in the entire […]
Briffa’s Ph.D. student, Thomas Melvin, discusses the important impact of “modern sample bias” on RCS chronologies, discussing Tornetrask and Finnish sites in detail.
Here’s a beautiful picture of a foxtail pine from the MWP, illustrating eloquently the change in treelines: Original Caption: A dead trunk above current treeline from a foxtail pine that lived about 1000 years ago near Bighorn Plateau in Sequoia National Park.
In my post on Tornetrask showing the impact of the Briffa-Jones "adjustment", I didn’t comment on confidence intervals.
The inquiry about the impact of alpha trees reminded me of a cute little diagram truncation by Briffa, Jones et al.
I have some odds and ends in inventory about bristlecone and foxtail sites, which I’m going to post up, mostly because I find the information rather interesting. Most dendrochronologists assume that the bristlecone/foxtail sites are far too remote to have experienced direct human effects. As far as I’m concerned, this is an assumption that needs […]
Here is a type of diagram which I often do on tree ring data. I’ve never seen anything like this in the tree ring literature, but some of you may be interested.
The Polar Urals tree ring site is another staple of multiproxy studies, being used in Bradley and Jones [1993], Hughes and Diaz[1994], Overpeck et al. [1997], Jones et al. [1998], MBH98, MBH99, Crowley and Lowery [2000], Esper et al. [2002], Bradley, Hughes and Diaz [2003] and Rutherford et al. [2005] (which recycles MBH98). In fact, […]
