INTERANNUAL VARIABILITY OF DEEP-WATER FORMATION IN THE NORTHWESTERN MEDITERRANEAN

In the Gulf of Lions, observations of deep convection have been sporad ically carried out over the past three decades, showing significant in terannual variability of convection activity. As long time series of m eteorological observations of the region are available from coastal st ations, heat flux time series for the Gulf of Lions for the individual winters from 1969 to 1994 are derived by calibrating these observatio ns against direct measurements obtained over the convection site. Thes e heat fluxes are also compared against heat fluxes obtained by the Fr ench PERIDOT weather model for the winter of 1991/92. A Kraus-Turner o ne-dimensional mixed layer model is initialized by climatological mean temperature and salinity profiles and then driven by the heat flux ti me series of the individual years. Resulting convection depths are in satisfactory agreement with existing observational evidence, showing t he dominance of interannual variability of local forcing on convection variability. The interannual variability of convection depth causes i nterannual variations in deep-water properties, and these are also com pared with the hydrographic database.