The effect of land-fast sea ice on coastal currents driven by the wind
Keiichirou Ohshima
Hokkaido Univ, N-19 W-8, Kita-Ku
Sapporo 060-0819, Japan
Tel: 81-11-706-5481
Fax: 81-11-706-7142
kay@lt.hines.hokudai. ac.jp
In polar regions some coastal oceans are often covered with land-fast sea ice. Since the stationary ice prevents the water beneath it from feeling the wind blowing over it, response of the ocean to the wind strongly depends on the existence of the fast ice. Even for the uniform wind, at the edge of the fast ice infinite stress curlacts on the ocean, which gives rise to excitation of the currents. First response of the coastal ocean to the fluctuating wind in the presense of land-fast sea ice is examined, assuming barotropic and long-wave approximation. It is found that__ excitation ratio of each shelf wave mode strongly depends on the ice edge location. For instance, the 1st mode is the prevailing mode in the case of no fast ice while it is much less excited with the ice edge advancing toward the shelf break. Next the response to the steady wind is also examined. It is shown that near the coast the current direction is the same as the wind stress direction in the case of no fast ice while it is reversed in the case where the ice edge is located at the shelf break.
