On the dynamics of the Pomeranian Bight

CTD and ADCP measurements were obtained from the Pomeranian Bight, on cruises of 2–3 weeks duration together with time-series measurements of currents and salinity, from 1993 to 1996, in different seasons of the year. The observations were supported by high-resolution circulation model runs, representing the whole of the Baltic Sea. del results and current/salinity observations in the Pomeranian Bight reveal the remote impact of both barotropic and baroclinic processes. The remote barotropic impact is driven by the exchange processes between the North Sea and the Baltic Sea. The process is controlled by a coherent band of intensive barotropic jets, which follow the north coast of Rügen Island, the northern edge of the Pomeranian Bight, and the central and easterly parts of the Pomeranian coast. This barotropic circulation pattern shelters the southern part of the Pomeranian Bight, from intensive currents. mote baroclinic impact is due to the density difference between the surface waters of the Arkona Basin and the Pomeranian Bight. It drives a southward-directed current along the east coast of Rügen Island, as far south as Greifswalder Oie Island. This baroclinic current is essential for maintaining the salt balance of the Pomeranian Bight, but it hampers the wind-driven flow of water from moving along the northwestern rim of the Pomeranian Bight, along the eastern coast of Rügen Island in the direction of the Arkona Basin. namical regime of the southern part of the Pomeranian Bight is governed by a locally wind-driven Ekman current and a compensating bottom current, as well as by coastal jets; these are weakest near the Swina river mouth and increase eastwards. differences were observed in the development of the river plumes in response to westerly and easterly wind forcing. The lagoon waters were transported in a narrow band along the Pomeranian coast, during westerly winds. Easterly winds of more than a few days duration cause the band of lagoon waters to be dispersed, by upwelling filaments in the offshore direction into the Bornholm Basin. Simultaneously, outflowing lagoon waters form stable plumes off the Usedom coast, which are restricted by a topographical ridge to the west of the Greifswalder Oie Island and the southward-directed salt flow along the east coast of Rügen Island, from flowing directly northwards into the Arkona Basin. However, Ekman transport associated with long-lasting southeasterly wind transports the plume towards the western edge of the Oderbank, where a northward-directed edge current carries the lagoon water plume into the Arkona Basin.