Air-sea interaction and penetrating winter convection in the Greenland Sea

Since 1984 research vessels of the Arctic and Antarctic Research Institute have carried out continuous studies in the central Greenland Sea, where the development of winter convection, penetrating down to the bottom, is possible. At the present time more than 20 oceanographic surveys have been made in this area, with 10 surveys conducted in winter (January-April). Penetrating convection events were observed in March 1984, 1988 and 1989. The strongest event was observed in March 1984, a somewhat less extensive event occurred in March 1989 and a relatively weak one occurred in winter 1988. The analysis of distributions of thermodynamic characteristics of water masses in the convection area allowed us to define major features of seasonal and inter-annual changes of vertical water structure, and to single out necessary conditions and stages of the penetrating convection development, which generally agree with the existing understanding, but which were supplemented by the indication of a specific role of atmospheric processes over the Greenland Sea. Quantitative estimates of the possible volume of bottom and deep waters forming in the penetrating convection events were made. The climate-forming role of this process and the possibility of forecasting it are discussed