HYDROGRAPHIC VARIABILITY OFF THE RIAS BAIXAS (NW SPAIN) DURING THE UPWELLING SEASON

During the Galicia X cruise, from May to October 1989 an intensive col lection of hydrographic data was carried out at a single station on th e shelf off the western coast of Galicia. It allows us to follow the r esponse of the water column to the intermittent equatorward wind stres s during the upwelling season. Upwelling events occur with biweekly pe riodicity, bringing Eastern North Atlantic Water (ENAW) to the subsurf ace layer at our station. A trend of the thermohaline properties of th e upwelled water to increase in time was observed. This seems to be mo stly due to the southwestward displacement of the origin of this water mass during the year. Although the saltier and warmer ENAW is less nu trient-rich, nutrient levels increase because of the rapid remineraliz ation of organic matter from the Rias, which takes place in the bottom water on the shelf.