Convection in the Greenland Sea, 1982-1993

Convection in the Greenland Sea is studied, using chlorofluorocarbons (CFCs, components F11, F12) and hydrographic distributions taken in spring 1993. A comparison with CFC data in the Greenland Sea Deep Water taken in 1989 shows that the CFC concentrations increased ony slightly, that is the deep convection activity below 2200 m depth remained on the very low level of the previous years 1982-1989. A simple convection model shows that in the depth range 550-2250 m the mean annual convection rate ceased significantly in the period from 1989 to 1993 compared to the previous years 1882-1989. For the upper 500 m, the modeled tracer concentrations deviate from the observations, most likely due to horizontal advection, neglected in the model.