RESEARCH HIGHLIGHT

Paper selected for AGU Journal Highlight

EOS, Vol. 88, No. 18, P. 204, 1 May 2007

Improved modeling of permafrost dynamics in global climate models

D. J. Nicolsky and V. E. Romanovsky: Geophysical Institute, University
of Alaska Fairbanks, Fairbanks, Alaska, U.S.A.;

V. A. Alexeev: International Arctic Research Center, University of
Alaska Fairbanks, Fairbanks, Alaska, U.S.A.;

D. M. Lawrence: National Center for Atmospheric Research, Boulder,
Colorado, U.S.A.

Across extensive areas in the Arctic and sub-Arctic, climate change will
likely transform soil temperature regimes and degrade permafrost.
Because permafrost covers about 25% of the land surface in the Northern
Hemisphere, degradation will change hydrological systems and feed back
to affect climate. Global climate models (GCMs) are frequently used to
understand and predict future climate change, but most GCMs do not
attempt to represent permafrost dynamics and their climate feedbacks.
To improve permafrost and soil temperature simulations, Nicolsky et al.
compared direct permafrost observations to the frequently-used Community
Land Model (CLM3) GCM. Through this comparison, they were able to
recommend specific modifications to the CLM3 which include increasing
the model's total soil depth by adding new layers, incorporating a
surface organic soil layer, and modifying the model's numerical scheme
to include unfrozen water dynamics and more realistic representation of
phase changes between ice and water.

- Mohi Kumar, AGU Journal Staff Writer

Figure 1. The air temperature and snow comer used to compute the volumetric ice content at Deadhorse for (right) 80m and (left) 3.43m thick soil columns without an organic lyer.

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Reference:
Nicolsky DJ, VE Romanovsky, VA Alexeev, DM Lawrence. 2007. Improved modeling of permafrost dynamics in global climate models. Geophysical Research Letters 34(8): Art No. Lo8501 APR 18 2007.

This material is subject to Copyright (2007) by the American Geophysical Union.