Abstract
The inter-annual variability characteristics of the winter convection in the Gulf of Lion in the Mediterranean Sea are studied using a high resolution model. After a 15-year spinup, the model was forced by the European Centre for Medium-range Weather Forecast (ECMWF) analyses from 1998 to 2008. Deep convection (> 500m) occurs in the MEDOC zone [40, 43.5 °N; 3, 7 °E south of the Gulf of Lion] in a quasi circular area of diameter of about 234km. While shallow deepening of the mixed layer to a depth of 400m only is noticed in the Ligurian Sea and eastern Catalan sub-basins, convection is much deeper in the Gulf of Lion and reaches the sea bottom in the winter of 2005. The location, the maximum depth, the duration and the formation rate of convection vary inter-annually. Compared to observations the hydrographic characteristics are slightly less dense by 0.01 mainly due to an offset in temperature of about 0.2°C. The spreading of the deep waters shows a cyclonic circulation. From the Gulf of Lion, the deep current flows southward along the eastern coast of Menorca. Then it splits in two directions, the first vein flows toward Gibraltar along the southern shelf of the Balearic Islands and the second vein toward the Gulf of Lion, where it interacts with mesoscale eddies and gyres.