CGRG Bibliography of Canadian Geomorphology
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Author : Beltrami, H.; and Bourlon, E.
Date : 2004.
Title : Ground warming patterns in the northern hemisphere during the last five centuries.
Publication : Eos Transactions. Joint Assembly of the CGU, AGU, SEG and EEGS, Montreal, Canada, May 17-21, 2004.
Issue : 85(17):
Page(s) : GC44A-03.
Abstract
Changes in the Earth's surface energy balance recorded underground have been used to reconstruct the temperature of the ground surface for the last 500 years in the northern hemisphere. We reconstructed ground surface temperature histories (GSTHs) from temperature versus depth profiles measured in 558 sites distributed between 30\deg and 60\deg N in the northern hemisphere using an inversion algorithm based on singular value decomposition. We show that that the ground has warmed about 1.0 K in the last 500 years. Spatial analysis reveals that spatial variability is important. Local short term oscillations are superposed to the general warming trend. Recent cooling is observed in Canada and Central Europe. The largest warming occurred during the last 50 years over the whole hemisphere and is more intense over the North American continent and South-Eastern Asia. To facilitate comparisons with previous northern hemisphere studies we computed an hemispheric average using several spatial averaging methods including a "cosine" projection algorithm. Although ground surface and air temperatures comparison is rather problematic, the weighted average northern hemisphere GSTH shows some consistency with multiproxy reconstructions for the last two centuries.
Bibliography of Canadian Geomorphology