Observations of the Mediterranean Undercurrent and eddies in the Gulf of Cadiz during 2001

The North Atlantic is strongly influenced by the presence of a high salinity and temperature water mass – the Mediterranean Water (MW) – lying at intermediate levels. A detailed field survey in the region around the Portimão Canyon, which constitutes the first large canyon that the Mediterranean Undercurrent encounters downstream of the Strait of Gibraltar, has been repeated in three different seasonal conditions (winter, spring and summer) of the year 2001, in the frame of Project MEDTOP. This paper is based on the observations undertaken during MEDTOP and focus on relevant aspects of the thermohaline and velocity fields associated with the Mediterranean Undercurrent and the associated eddies, bringing further evidence of hypotheses presented in previous work on the dynamical behaviour of the Mediterranean Outflow and its intra-annual variability, and describing new observations of meddy formation and subsequent evolution in the centre of the Gulf of Cadiz.