National Research Council of Italy, Department of Earth and Environment
Abstract
An international research program was devoted to understanding the dynamic properties of the mesoscale circulation in the Adriatic Sea such as fronts, eddies, coastal filaments, river inflow and study the effects of forcing by winds and river run-offs. The present work focuses specifically on the impact of the Po river outflow on the biochemical properties along the western Adriatic coast under different conditions of river discharge and wind stress in winter and spring. In the winter cruise, the satellite images show a strong front in the northern part of the Adriatic extending from the Italian coast to the Istrian Peninsula. In situ measures showed that the northern water mass was characterized by low temperature and salinity, and high nutrient and chlorophyll concentrations due to a strong Bora event which expanded the Po River plume towards the Istrian Peninsula instead of southwards in the West Adriatic Current. During the spring cruise, wind forcing was quite weak and the volume flux from the Po River was about one third of its mean discharge for this period of the year. Off the Po River, the water column was characterized by a surface layer with low salinity and high dissolved inorganic nitrogen and chlorophyll. This water mass did not extend as far eastwards as in winter because the wind forcing was not nearly as important and the alongshore plume extended southward along the Italian Coast