Cooperative Institute for Research in Environmental Sciences

Northern Alaskan Land Surface Response to Reduced Arctic Sea Ice Extent

Higgins, M.E., and J.J. Cassano

2012, Climate Dynamics, 38, 2099-2113, doi:10.1007/s00382-011-1095-0

With Arctic sea ice extent at near-record lows, an improved understanding of the relationship between sea ice and the land surface is warranted. We examine the land surface response to changing sea ice by first conducting a simulation using the Community Atmospheric Model (CAM) version 3.1 with end of the 21st century sea ice extent. This future atmospheric response is then used to force the Weather and Research Forecasting Model (WRF) version 3.1 to examine the terrestrial land surface response at high resolution over the North Slope of Alaska. Similar control simulations with 20th century sea ice projections are also performed, and in both simulations only sea ice extent is altered. In the future sea ice extent experiment, atmospheric temperature increases significantly due to increases in latent and sensible heat flux, particularly in the winter season. Precipitation and snow pack increase significantly, and the increased snow pack contributes to warmer soil temperatures for most seasons by insulating the land surface. In the summer, however, soil temperatures are reduced due to increased albedo. Despite warmer near-surface atmospheric temperatures, it is found that spring melt is delayed throughout much of the North Slope due to the increased snow pack, and the growing season length is shortened.