MODELING OF THE GREENLAND, ICELAND, AND NORWEGIAN SEAS WITH A COUPLED SEA-ICE MIXED-LAYER ISOPYCNIC OCEAN MODEL

A coupled sea ice - mixed layer - isopycnal ocean model is used to simulate the circulation in the Greenland, Iceland, and Norwegian (GIN) Seas. The model domain consists of the North Atlantic, including the GIN Sea and the Arctic Ocean. The Atlantic Ocean is bounded meridionally at about 10 degrees S, and in the Arctic the Bering Strait is closed. In order to obtain sufficient resolution of the current system in the GIN Sea, the horizontal resolution increases from 2 degrees x 2 degrees near the equator and in the Pacific sector of the Arctic to less than 30 km x 30 km in the GIN Sea. As initial conditions, observed annual mean temperature and salinity are used. The surface-forcing fields are determined from monthly mean atmospheric quantities. The surface salinity is prescribed (with a weak Newtonian relaxation coupling) as an annual mean. Except for the deep ocean, the GIN Sea adjusts to its own physics after a few years. Longer timescales are introduced owing to the interactions with the North Atlantic and the Arctic Oceans. The salinity in the GIN Sea has become slightly lower than the initial data. The general convection depth is consistent with observations during the 1980s; Ice fluxes and the fluxes in the upper ocean are consistent with previous estimates. The outflow of intermediate and deep water into the North Atlantic is underestimated. However, the model reproduces the main features of the ice-ocean circulation in the GIN Sea and the adjacent basins.