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Twentieth century Antarctic air temperature and snowfall simulations by IPCC climate models
Author(s) -
Monaghan Andrew J.,
Bromwich David H.,
Schneider David P.
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl032630
Subject(s) - climatology , snow , surface air temperature , environmental science , radiative forcing , future sea level , atmospheric sciences , climate sensitivity , climate change , climate model , antarctic ice sheet , forcing (mathematics) , global temperature , ice sheet , cryosphere , global warming , meteorology , sea ice , ice stream , geology , geography , oceanography
We compare new observationally‐based data sets of Antarctic near‐surface air temperature and snowfall accumulation with 20th century simulations from global climate models (GCMs) that support the Intergovernmental Panel on Climate Change Fourth Assessment Report. Annual Antarctic snowfall accumulation trends in the GCMs agree with observations during 1960–1999, and the sensitivity of snowfall accumulation to near‐surface air temperature fluctuations is approximately the same as observed, about 5% K −1 . Thus if Antarctic temperatures rise as projected, snowfall increases may partially offset ice sheet mass loss by mitigating an additional 1 mm y −1 of global sea level rise by 2100. However, 20th century (1880–1999) annual Antarctic near‐surface air temperature trends in the GCMs are about 2.5‐to‐5 times larger‐than‐observed, possibly due to the radiative impact of unrealistic increases in water vapor. Resolving the relative contributions of dynamic and radiative forcing on Antarctic temperature variability in GCMs will lead to more robust 21st century projections.