Rune Grand Graversen’s Doctor Thesis (FN 1) assumes that: „A major topic is the linkage between the mid-latidude circulation and the Arctic warming. It is suggested that the atmospheric merdional energy transport is an efficient indicator of this linkage“.
This website discussed his recent Nature paper in January 2008 (see Archive). The thesis claims that since the 1970s, a warming trend reached almost 0,5ºC per decade, while during the 1930s through the 40s, a weaker Arctic amplification is observed. Such ascertainment indicates that little efforts have been made to understand the used data. Already back in 1922 the US Monthly Weather Report reported that the Gulf Stream ensured exceptional low ice conditions high in the North Atlantic (FN 2), and this website provides ample information and graphs to prove this as well.
When Graversen concludes that the snow and ice-albedo feedbacks are a contributing but not dominating mechanism behind the Arctic amplification, and that a coupled climate-model experiment with a doubling of the atmospheric CO2 concentration reveals a considerable Arctic surface-air-temperature amplification in a world without surface-albedo feedback, one is left to wonder, why such a thesis ignores completely the extreme winter warming from 1918 to 1922 which lasted until 1940 acknowledged by Igor V. Polyakov et.al, 2003. In this scenario CO2 is presumably the weakest mean to influence surface temperatures, and climate modelling is hardly a helpful tool, as long as not more distinctions between the sunless winter season and summer time is made.
H.W. Ahlmann provided already back in 1946 a detailed account on observed regression of glaciers and inland ice in Norway and other locations in the northern Hemisphere from 1918-1940. The retreat of sea ice in the Spitsbergen region due to ‘recent climatic improvement’ forced him to note that: “This part of the Arctic may, without exaggeration, be said to have experienced a climatic revolution”. (see here left column: Chapter B, How the warming was discussed until the 1940s).
As the defence of the thesis is in a few days time (Defence: 2008-04-25), the Arctic-Warming.Com-Team is wishing Rune Grand Graversen a very successful examination and an excellent result.
(FN 2) http://www.jennifermarohasy.com/blog/archives/002847.html; March 18, 2008; Arctic Warming: Radical Changes in Climatic Conditions Observed; with attribute to: Anthony Watts, for locating this.