Accelerated Arctic Land Warming and Permafrost Degradation during Rapid Sea Ice Loss


Simulations of the Community Climate System Model (CCSM) suggest periods of rapid Arctic sea ice loss in the next 50 years. In 2007, Arctic sea ice shrank to more than 30 percent below average, a modern-day record. From August to October last year, air temperatures over the western Arctic were also unusually warm, reaching more than 2°C above the 1978-2006 average. This raises the question of whether or not unusually low sea-ice and warm land temperatures are related. In a study published in the June 13, 2008 issue of Geophysical Research Letters, SC researcher David Lawrence and colleagues from the National Center for Atmospheric Research found that simulated western Arctic land warming trends during rapid sea ice loss were 3.5 times greater than average simulated 21st century climate-change trends. The accelerated warming also penetrated up to 1500km inland throughout most of the year, peaking in autumn. Experiments using the Community Land Model (the land component of the CCSM) indicate that an accelerated warming period substantially increases ground heat accumulation leading to rapid degradation of warm permafrost and possibly increasing the vulnerability of colder permafrost to degradation. These results imply a link between rapid sea ice loss, permafrost health, and Arctic land warming.


Lawrence, D.M., A.G. Slater, R.A. Tomas, M.M. Holland, and C. Deser. 2008. “Accelerated Arctic land warming and permafrost degradation during rapid sea ice loss,” Geophys. Res. Lett. 35 L11506, DOI:10.1029/2008GL033985.