Why does the Antarctic Peninsula Warm in climate simulations?

The Antarctic Peninsula has warmed significantly since the 1950s. This pronounced and isolated warming trend is collectively captured by 29 twentieth century climate hindcasts participating in the version 3 Coupled Model Intercomparison Project. To understand the factors driving warming trends in th...

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Bibliographic Details
Main Authors: Xin Qu, Alex Hall, Julien Boé
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2011
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.389.4812
http://www.atmos.ucla.edu/csrl/publications/Hall/Qu_et_al_1_11_2011.pdf
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Summary:The Antarctic Peninsula has warmed significantly since the 1950s. This pronounced and isolated warming trend is collectively captured by 29 twentieth century climate hindcasts participating in the version 3 Coupled Model Intercomparison Project. To understand the factors driving warming trends in the hindcasts, we examine trends in Peninsula region’s atmospheric heat budget in every simulation. We find that atmospheric latent heat release increases in nearly all hindcasts. These increases are generally anthropogenic in origin, and account for about 60 % of the ensemble-mean warming trend in the Peninsula. They are driven primarily by wellunderstood features of the anthropogenic intensification of global hydrological cycle. As sea surface temperature increases, moisture contained in atmospheric flows increases. When such flows are forced to ascend the Peninsula’s topography, enhanced local latent heat release results. The mechanism driving the warming of the Antarctic Peninsula is therefore clear in the models. Evidence for a similar mechanism operating in the real world is seen in the increasing snow accumulation rates inferred from ice cores drilled in the Peninsula. However, the relative importance of this mechanism and other processes previously identified as potentially causing the observed warming, such as the recent sea ice retreat in the Bellingshausen Sea, is difficult to assess. Thus the relevance of