Author Archives: Hu McCulloch

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 […]

Mann on Irreproducible Results in Thompson (PNAS 2006)

Michael Mann’s new book, The Hockey Stick and the Climate Wars, discusses my comment [SMc note – this post is by Hu McCulloch] , “Irreproducible Results in Thompson et al., ‘Abrupt Tropical Climate Change: Past and Present’ (PNAS 2006),” that was published in 2009 in Energy & Environment. My comment pertained to an article by […]

Kriging on a Geoid

Geoff Sherrington and others on the First Difference Method post have requested a post for discussing Kriging. I am new to Kriging myself, so please correct me if I make any errors here. Steve McIntyre (who may be on the beach at the moment!) is far more knowledgeable, and has posted about the topic frequently […]

The First Difference Method

Over on WUWT (, Zeke Hausfarther and Steven Mosher have been discussing the calculation of global temperature from station data. They list several methods of combining records, noting that most of the major indices use the Common Anomalies Method (CAM). They mention, but do not discuss, the First Differences Method (FDM). In fact, FDM is […]

Calibrating “Dr. Thompson’s Thermometer”

One of the most persuasive images in the global warming debate is a graph that Al Gore describes in his An Inconvenient Truth as “Dr. Thompson’s thermometer.” According to Gore, this graph is based on oxygen isotope ratios from ice cores collected by Lonnie Thompson and his colleagues, and provides “the most definitive” independent confirmation […]

Invalid Calibration in Kaufman 2009

Darrell S. Kaufman, David P. Schneider, Nicholas P. McKay, Caspar M. Ammann, Raymond S. Bradley, Keith R. Briffa, Gifford H. Miller, Bette L. Otto-Bliesner, Jonthan T. Overpeck, and Bo M. Vinther (Science 9/4/2009) propose a reconstruction of Arctic summer land temperatures for the last 2000 years, using 23 diverse proxies. Decadal averages of each proxy […]

Spline Smoothing

The 2009 Climate Dynamics paper “Unprecedented low twentieth century winter sea ice extent in the Western Nordic Seas since A.D. 1200” by M. Macias Fauria, A. Grinsted, et al. discussed already on the thread Svalbard’s Lost Decades pre-smooths its data with a 5-year cubic spline before running its regressions. There’s been a lot of discussion […]

Svalbard’s Lost Decades

In a 2006 article in JGR, Aslak Grinsted, John Moore, Viejo Pohjola, Tonu Martma and Elisabeth Isaksson study several climate indicators from the Lomonosovfonna ice field in Svalbard, shown below with their caption: Figure 5. Fifteen-year moving averages of Lomonosovfonna ice core data. (a) Oxygen isotopes, (b) continentality proxy (A), (c) stratigraphic melt indices (SMI), […]

Steig Professes Ignorance

On Feb. 26, I wrote a post on CA, “Steig 2009’s Non-Correction for Serial Correlation”, commenting on the Jan. 22 letter in Nature by Eric Steig et al. On Feb. 28, I sent Steig and his 5 co-authors an e-mail alerting them to my post and its content. On Aug. 6, Steig and co-authors published […]

Irreproducible Results in PNAS

In Al Gore’s movie and book An Inconvenient Truth, he presents a graph which he identifies [in the book] as “Dr. Thompson’s Thermometer.” Gore attributes this graph to the ice core research of Lonnie Thompson, and says [in the book] that it provides independent evidence for the validity of the “Hockey Stick” temperature reconstruction of Michael Mann […]