TIMING OF DEEP CONVECTION IN THE GREENLAND AND ICELAND SEAS

This paper reviews published information on the timing of hydrographic and atmospheric variations in the Iceland and Greenland Seas. Large s cale variations in hydrography, advection features, regional convectio n and their general impact or connection with climate and hydro-biolog ical conditions will be considered briefly in the area of the Subarcti c Gyre in the northern North Atlantic and the Nordic Seas. The interme diate convection in the Iceland Sea may have ceased during the so-call ed ''ice years'' in North Icelandic waters in the late sixties (1965-1 970). Convection to the bottom in the Greenland Sea seems to have ceas ed in the seventies or after 1972. A clear linkage between the period of the ''Great Salinity Anomaly'', that was first observed in the Icel and Sea around 1968 and was advected through the Subarctic Gyre and re turned to East Greenland waters and North Icelandic waters in 1981, an d the timing of reduction of convection in the Greenland Sea is thus n ot obvious. Further detailed analysis is needed to resolve the questio ns about processes involved in the variability of hydrographic conditi ons in the northern North Atlantic and the Nordic Seas. It should be n oted that conditions for convection may not only be related to atmosph eric conditions or large scale advection of water characteristics but also to regional or local hydrographic conditions. (C) 1997 Internatio nal Council for the Exploration of the Sea.