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• Main Authors: Marika M. Holland, Cecilia M. Bitz, Elizabeth C. Hunke, William H. Lipscomb, Julie L. Schramm
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2005
• Subjects: Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.422.1737; http://www.cesm.ucar.edu/publications/jclim04/Papers/PCWG1.pdf

We present the sea ice simulation of the CCSM3 T42-gx1 and T85-gx1 control simulations and examine the influence of the parameterized sea ice thickness distribution (ITD) on polar climate conditions. This includes an analysis of the change in mean climate conditions and simulated sea ice feedbacks when an ITD is included. We find that including a representation of the sub-gridscale ITD results in larger ice growth rates and thicker sea ice. These larger growth rates represent a higher heat loss from the ocean-ice column to the atmosphere, resulting in warmer surface conditions. Ocean circulation, most notably in the southern hemisphere is also modified by the ITD because of the influence of enhanced high latitude ice formation on the ocean buoyancy flux and resulting deep water formation. Changes in atmospheric circulation also result, again most notably in the southern hemisphere. There are indications that the ITD also modifies simulated sea ice related feedbacks. In regions of similar ice thickness, the surface albedo changes at 2XCO2 conditions are larger when an ITD is included, suggesting an enhanced surface albedo feedback. The presence of an ITD also modifies the ice thickness-ice strength relationship and the ice thickness-ice growth rate relationship, both of which represent negative feedbacks on ice thickness. The net influence of the ITD on polar climate sensitivity and variability results from the interaction of these and other complex feedback processes. 2