Category Archives: Proxies

Alkenone Divergence in Peru

Gutierrez et al (GRL 2011) pdf here; data here is another very high resolution alkenone series that is well-dated in the 20th century. It was taken in an upwelling zone offshore Peru at a similar latitude to Quelccaya. Like the high-resolution series offshore Morocco and Namibia, it shows a sharp decline in alkenone-estimated SST in […]

Alkenone Divergence

While there are disappointingly few high-resolution alkenone ocean cores with 20th century resolution, there are a few. Given the importance of this class of proxy in Marcott et al, one would have thought the performance of high-resolution alkenones in the 20th century would have been of interest to Marcott et al, but they were silent […]

The Quelccaya Update

Lonnie Thompson has done a much better job of archiving data for his recent update Quelccaya – see NOAA here – both in terms of information and promptness. Quelccaya is familiar territory for Thompson as it was the location of his first tropical ice cores (1983) and his first publication of this type. Thompson published […]

Bent Their Core Tops In

In today’s post, I’m going to show Marcott-Shakun redating in several relevant cases. The problem, as I’ve said on numerous occasions, has nothing to do with the very slight recalibration of radiocarbon dates from CALIB 6.0.1 (essentially negligible in the modern period in discussion here), but with Marcott-Shakun core top redating.

Hiding the Decline: MD01-2421

As noted in my previous post, Marcott, Shakun, Clark and Mix disappeared two alkenone cores from the 1940 population, both of which were highly negative. In addition, they made some surprising additions to the 1940 population, including three cores whose coretops were dated by competent specialists 500-1000 years earlier. While the article says that ages […]

The Marcott-Shakun Dating Service

Marcott, Shakun, Clark and Mix did not use the published dates for ocean cores, instead substituting their own dates. The validity of Marcott-Shakun re-dating will be discussed below, but first, to show that the re-dating “matters” (TM-climate science), here is a graph showing reconstructions using alkenones (31 of 73 proxies) in Marcott style, comparing the […]

Lonnie Thompson’s Legacy

In my last post, I observed that Ellen Mosley-Thompson’s archiving record was even worse than that that of her husband, Lonnie Thompson, whose failure to adequately archive his ice core measurements has long been a subject of criticism at Climate Audit. In particular, I observed that Ellen had archived nothing from the 15 expeditions to […]

Lonnie and Ellen, A Serial Non-Archiving Couple

Recently, Geoffrey Boulton’s report and Nature editorial provided more pious language urging data archiving by hoarding scientists. As I mentioned in my initial comments on Boulton’s editorial, there have been many such pious pronouncements over the years without the slightest impact on, for example, the serial non-archiving couple of Lonnie Thompson and Ellen Mosley-Thompson, who, […]

Screening Proxies: Is It Just a Lot of Noise?

There has been a great deal of discussion on a recent CA thread on the efficacy of screening proxies for use in reconstructions by selecting on the size of the correlation between the proxy and the temperature during the calibration time period. During the discussion I asked Nick Stokes the following questions in a comment: […]

Thompson Gets New NSF Grant

Lonnie Thompson, senior research scientist at Ohio State University’s Byrd Polar Research Center, and his colleague Paolo Gabrielli, have just been awarded a three-year $588,000 grant from the NSF’s Division of Atmospheric and Geophysical Sciences “to assess the human impact on the chemical characteristics of the glaciers in the Himalaya and the Tibetan Plateau from […]


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