Climatology of geostrophic currents in the Northern Adriatic

Abstract

Climatology of the geostrophic currents in the northern Adriatic, based on a large amount of historical data, is documented. The geostrophic circulation can be resolved into the winter circulation, the summer circulation and transition circulations in spring (April and May) and in autumn (September and October). There is a permanent existence of a local cyclonic gyre in Trieste Bay and a northern Adriatic (NAd) current connected with western-middle Adriatic (W-MAd) current throughout the year. During the winter period the circulation in the northern Adriatic is a part of the global Adriatic cyclonic gyre. In the spring starts the meandering of low-salinity water toward the east. This anticyclonic meander comes to the Istrian coast in August and September in conjunction with the Istrian coastal countercurrent (ICCC), suggesting the existence of a sharply defined eastward moving anticyclonic meander from June to September. There is good agreement in August and September between measured residual and calculated baroclinic currents. The northern Adriatic (NAd) cyclonic gyre is present only in December.