Tag Archives: khadyta

New Data from Hantemirov

Yesterday, I received updated Yamal data (to 2005) from Rashit Hantemirov, together with a cordial cover note. As CA and other readers know, Hantemirov had also promptly sent me data for Hantemirov and Shiyatov 2002. There are 120 cores in the data set, which comes up to 2005. I’ve calculated a chronology from this information […]

Yamal FOI Sheds New Light on Flawed Data

Phil Jones’ first instinct on learning about Climategate was that it was linked to the Yamal controversy that was in the air in the weeks leading up to Climategate. I had speculated that CRU must have done calculations for Yamal along the lines of the regional chronology for Taimyr published in Briffa et al 2008. […]

Yamal and Hide-the-Decline

In The Climate Files, Fred Pearce wrote: When I phoned Jones on the day the emails were published online and asked him what he thought was behind it, he said” It’s about Yamal, I think”. Pearce continued (p 53): The word turns up in 100 separate emails, more than ‘hockey stick’ or any other totem […]

Yamal and the Decline

Contrary to a myth believed in by the climate science “community”, most recent multiproxy reconstructions are not “independent” – they merely recycle the same stereotypes with slightly different weighting methods. In an email (1140039406.txt) in which Briffa urges Overpeck not not to “over egg the pudding”, he stated: “Peck, you have to consider that since […]

Yamal and the Vaganov Network

As a spin-off from looking at Mann of Oak proxies, I did (what I regard) as a pretty bit of decoding of some measurement data in the Climategate documents. The Climategate directory documents/briffa-treering-external/stepan/ contains a large number of tree ring measurement files dated July 1996 (with the characteristic suffix .rwl) with 3-character labels, “ala” “all” […]

What Happened to Polar Urals?

Addiction of paleoclimate reconstructions to particular proxies has been a longstanding concern at Climate Audit. One of the battleground issues has been the addiction to Briffa’s Yamal tree ring series, while the nearby update of Polar Urals (with a pronounced MWP) was disappeared. (See CA category.) Just before Climategate, we raised questions about the Yamal […]

Is Yamal Homogeneous? An Esper-Style Answer.

Starting with the first of my recent posts on Yamal, I raised the issue of whether the CRU 12 actually came from a homogeneous population to the subfossil population. Although Briffa’s online response to my Yamal posts stated that CRU has “stressed” potential problems arising from “inhomogeneous” sources” in their “published work”, I have been […]

Response to Briffa #2

As noted at CA last week, Briffa published a partial response to Yamal issues at the CRU website, one post discussing the impact of the Yamal chronology in various studies and another post discussing the Yamal chronology itself. For a response to Briffa’s online article on the impact of Yamal, I refer readers to last […]

Esper et al 2009 on West Siberia

Esper et al (Global Change Biology, in press) “Trends and uncertainties in Siberian indicators of 20th century warming” is relevant to our present consideration of Briffa’s Yamal, which I will get to shortly. The cutline in their abstract declares in effect that the divergence problem is not as “bad as we thought”: Despite these large […]

Yamal and the Divergence Problem

One of the aspects of the Yamal discussion that is perhaps clearer to regular CA readers than to new readers is that Briffa’s Yamal chronology was very different from ring width chronologies previously reported in the area (including by Briffa itself.) Shortly after the publication of Osborn and Briffa 2006 and D’Arrigo et al 2006 […]