Author Archives: Stephen McIntyre

Polar Urals #1

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 […]

Pliocene #1: North Greenland

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 […]

"Modern Sample Bias", RCS and Briffa’s "Adjustment"

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.

Bristlecone/Foxtail #2: Bighorn Plateau

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.

Tornetrask #4: Confidence Intervals

In my post on Tornetrask showing the impact of the Briffa-Jones "adjustment", I didn’t comment on confidence intervals.

Tornetrask #3: A Truncated Diagram

The inquiry about the impact of alpha trees reminded me of a cute little diagram truncation by Briffa, Jones et al.

Bristlecone/Foxtail Site #1: Cirque Peak

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 […]

Tornetrask #2

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.

Altitude at Briffa’s Polar Urals

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, […]

Briffa’s Tornetrask Reconstruction

Briffa’s temperature reconstruction from Tornetrask (northern Sweden) tree rings is a staple of multiproxy studies, used in Bradley and Jones [1993], Hughes and Diaz [1994], Jones et al. [1998], MBH98, MBH99, Briffa and Crowley and Lowery [2000], Briffa et al. [2000], Bradley, Hughes and Diaz [2003], Mann and Jones [2003], Jones and Mann [2004]. Briffa […]