Bioclimate.org: Accelerated Arctic land warming and permafrost degradation during rapid ice loss

Authors	Lawrence D.M.
Source	The National Center for Atmospheric Research (NCAR) (2)
Type	P - Paper (2851)
Peer Review	2 - Medium (2288)
Audience	S - Specialist (3514)
Notes	NCAR/CGD Abstract. Coupled climate models and recent may undergo abrupt periods of loss within fifty years. Here, we evaluate the impact of rapid sea ice loss on terrestrial Arctic climate and ground thermal state in the Community Climate System Model. We find that western Arctic land warming trends during rapid sea ice loss are 3.5 times greater than secular 21st century climate-change trends outside these periods. The accelerated warming signal extends up to 1500km inland and is apparent throughout most of the year, peaking in autumn. Idealized experiments using the Community Land Model, with improved permafrost dynamics, indicate that an accelerated warming period substantially increases ground heat accumulation – the earlier the event the greater the long-term impact. For warm permafrost, enhanced heat accumulation can lead to rapid degradation. For colder ground, heat accumulation preconditions permafrost for earlier and/or more rapid degradation under continued warming.