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GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L07502, doi:10.1029/2007GL032630, 2008

Twentieth century Antarctic air temperature and snowfall simulations by IPCC climate models

Andrew J. Monaghan

Polar Meteorology Group, Byrd Polar Research Center, Ohio State University, Columbus, Ohio, USA


David H. Bromwich

Polar Meteorology Group, Byrd Polar Research Center, Ohio State University, Columbus, Ohio, USA
Atmospheric Sciences Program, Department of Geography, Ohio State University, Columbus, Ohio, USA


David P. Schneider

Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, Colorado, USA


Abstract

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.

Received 9 November 2007; accepted 6 March 2008; published 5 April 2008.

Keywords: Antarctica; temperature; GCMs.

Index Terms: 1621 Global Change: Cryospheric change (0776); 1626 Global Change: Global climate models (3337, 4928); 1637 Global Change: Regional climate change; 1641 Global Change: Sea level change (1222, 1225, 4556).

Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 272961 bytes)

Citation: Monaghan, A. J., D. H. Bromwich, and D. P. Schneider (2008), Twentieth century Antarctic air temperature and snowfall simulations by IPCC climate models, Geophys. Res. Lett., 35, L07502, doi:10.1029/2007GL032630.