WIND-INDUCED MESOSCALE FEATURES IN A COUPLED ICE-OCEAN SYSTEM

A quasi-geostrophic, mesoscale eddy-resolving model is coupled with free-drifting sea ice to examine mesoscale oceanic structures, which are induced by wind forcing on a nonuniform ice distribution, and redistribution of sea ice. Initial concentration of sea ice has anomalies on the motionless ocean, and the sea ice is suddenly forced by a wind stress. Differences in Ekman transport between the high (low) concentration area and the surrounding area generate dipole eddylike features in the ocean with anticyclonic and cyclonic eddies on the right (left) and left (right), respectively, looking in the downwind direction. Redistribution of ice by the ocean circulation continues after the wind ceases, forming arch or hammer head shapes of ice anomalies. Interactions with the other anomalies can produce various shapes, which could lead to misinterpretation of ocean flow field. It is suggested that to detect ocean flow field in an ice-covered area (not near the ice edge), trajectories should be used instead of shapes of ice cover.