Deep mixing in the Gulf of Lions, Revisited

Abstract

The Gulf of Lions, south of France, is a preferred location for deep convection in late winter as documented by the so‐called MEDOC studies during 1969‐73. During 23 January to 5 March 1987 a renewed investigation was carried out in this region to investigate the occurrence of deep convection with new technology. Vertical and horizontal currents were measured over a range of several hundred meters with moored upward‐looking acoustic Doppler current profilers (ADCPs); full‐depth horizontal current profiles were obtained by PEGASUS profiler; and CTD hydrography combined with measurements of some biological and chemical parameters to delineate watermass properties in the convection regime. A deep‐mixed patch had already developed at the beginning of the experiment, following a particularly intense mistral on 10/11 January. During a second mistral, 15‐20 February, vertical current events of 5‐15 cm/s downward were observed. Events were of short duration but large vertical scale.