Haline circulation induced by formation and melting of sea ice

Abstract

A three‐dimensional, coupled ice‐ocean model is developed, and basic numerical experiments for examining effects of freshwater budget associated with formation and melting of sea ice on the thermohaline circulation are performed. Motion of sea ice affects the freshwater budget in two ways. First, it horizontally transports freshwater in the form of sea ice. Second, it alters the conditions of sea ice, which influence heat budget at the sea surface and thus the rate of formation and melting. To separate such effects of ice motion, two experiments are designed. In one case, ice motion is removed, and in the other case it is included. There appear significant differences in the thermohaline circulation between the two cases. These differences are due to the difference in horizontal distribution of salinity, which is maintained by the cycle of formation, transport, and melting of sea ice and the corresponding freshwater budget. Experiments for investigating dependence of the thermohaline circulation on the distribution of winds and consequent ice motion are also carried out. It is demonstrated that wind‐induced ice motion has major influences on how saline water produced by sea ice formation at high latitudes extends.