Exploring the Role of Oceanic Feedbacks in the Atmospheric Circulation and Climate Response to Projected 21st Century Arctic Sea Ice Loss

We investigate the role of oceanic feedbacks in the atmospheric circulation and climate response to projected 21st century Arctic sea ice loss using targeted experiments with the latest version of the NCAR coupled climate model CCSM4. Localized oceanic feedbacks in the form of increased SSTs in areas of sea ice loss enhance the upward surface energy fluxes and result in a strengthened high-latitude atmospheric circulation response, particularly in winter. The addition of remote oceanic feedbacks, especially those in low latitudes, alters the distribution of tropical precipitation that in turn induces an atmospheric Rossby wave train response over middle and high latitudes. Thus, oceanic feedbacks substantially modify the direct atmospheric response to Arctic sea ice loss.