Modelling Study of Gulf of Cadiz Coastal Countercurrent

A.M. Teles-Machado, A. Peliz and J. Dubert
Physics Dept.(CESAM), University of Aveiro, Portugal


The Gulf of Cadiz in the Eastern North Atlantic, located south of Iberian Peninsula, is characterized by a complex circulation pattern influenced by diverse factors. Heterogeneous wind fields, caused by the abrupt change in coastline orientation; upwelling in the west, and some times southern Iberian coasts; the Mediterranean Undercurrent and the Eastern extention of the Azores Current. A modelling study using ROMS is conducted in order to simulate the Gulf of Cadiz circulation. The objective is to investigate the onset of a coastal warm countercurrent, usually associated with wind relaxation periods.

The current forms on northern Gulf of Cadiz and flows westward, eventually turning around Cape St Vicente and flowing northward along Portuguese west coast. The model reproduces well the current formation and at the same dates observed in satellite imagery. Atmospheric forcing fields were obtained from WRF model simulations for the summer period of 2000.

A number of experiments are described in which we change model forcing and initialization in order to understand the important mechanisms to the onset and driving of the current. The onset of the current is mainly controlled by the interaction of the wind with coastline irregularities, as it happens locally near important capes.