CCR's Climate Change Prediction Research

Permafrost Changes

Simulations by global climate models show that when sea ice is in rapid decline, the rate of predicted Arctic warming over land can more than triple. The image at left shows simulated autumn temperature trends during periods of rapid sea-ice loss, which can last for 5 to 10 years. The accelerated warming signal (ranging from red to dark red) reaches nearly 1,000 miles inland. In contrast, the image at right shows the comparatively milder but still substantial warming rates associated with rising amounts of greenhouse gas in the atmosphere and moderate sea-ice retreat that is expected during the 21st century. Most other parts of the globe shown in white will experience warming, but at a lower rate of less than 1 degree Fahrenheit (0.5 Celsius) per decade.


The contribution of snow condition trends to future ground climate

Abstract: Global climate models predict that terrestrial northern high-latitude snow conditions will change substantially over the twenty-first century. Results from a Community Climate System Model simulation of twentieth and twenty-first (SRES A1B scenario) century climate show increased winter snowfall (+10-40%), altered maximum snow depth (-5 ± 6 cm), and a shortened snow-season (-14 ± 7 days in spring, +20 ± 9 days in autumn). By conducting a series of prescribed snow experiments with the Community Land Model, we isolate how trends in snowfall, snow depth, and snow-season length affect soil temperature trends.

Citation: Lawrence, D.M., and A.G. Slater, 2009: The contribution of snow condition trends to future ground climate. Clim. Dyn., 10.1007/s00382-009-0537-4.

Accelerated Arctic land warming and permafrost degradation during rapid sea ice loss

Abstract: Coupled climate models and recent observational evidence suggest that Arctic sea ice may undergo abrupt periods of loss during the next fifty years. Here, we evaluate how rapid sea ice loss affects terrestrial Arctic climate and ground thermal state in the Community Climate System Model. We find that simulated western Arctic land warming trends during rapid sea ice loss are 3.5 times greater than secular 21st century climate-change trends. The accelerated warming signal penetrates up to 1500 km 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.

Citation: 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.