This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The primary goal of this project is to investigate the mechanisms underlying the seasonal response of the climate system to Arctic sea ice loss within the context of anthropogenic climate change. This research will utilize the NCAR Community Climate System Model, version 4 (CCSM4), which is a fully coupled global atmosphere-ocean-cryosphere-land model with terrestrial and oceanic carbon-nitrogen cycling capabilities. The overarching goal of this proposed effort is to investigate the relative roles of sea ice loss versus rising greenhouse gases for changes in the seasonal succession and timing of Arctic processes. This will involve research designed to assess the influence of seasonal sea ice loss on aspects of the marine, terrestrial, and atmospheric systems, with a particular emphasis on the seasonal dependence of the responses. This work will include a series of targeted sensitivity integrations to isolate processes of interest. These experiments will be evaluated within the context of available observations. This project will also assess the integrated effects of these various processes and how they in turn feed back onto the seasonality of Arctic sea ice change. Current and projected changes in the Arctic system have repercussions for the global climate system, Arctic wildlife, and socio-economic activities in the region. Improving our understanding and modeling of the factors affecting the seasonal timing and succession of processes within the Arctic system will allow for improved Arctic and global system predictability. This has a direct impact on the ability of society to anticipate, mitigate, and adapt to future change.
