A synthesis of the circulation and hydrography of the South Aegean Sea andthe Straits of the Cretan Arc (March 1994 January 1995)

Four seasonal oceanographic cruises were carried out in the Eastern Mediter ranean Sea, within the framework of the CEC/MAST-MTP Project PELAGOS, durin g 1994-1995. The surveys covered the South Aegean Sea and the adjacent open sea regions (southeastern Ionian, northwestern Levantine). Analysis of CTD data revealed that a multiscaled circulation pattern prevails in the area. It differs from the circulations detected during the 1986-87, thus indicat ing interannual variability. Cyclonic and anticyclonic gyres and eddies are interconnected by currents and jets variable in space and time. Most of th e features are persistent, others seem transitional or recurrent. The hydro logical structure is also complex and apart from the upper layer does not p resent basinwide any significant seasonality Dynamical and hydrological reg imes are variable in the upper and intermediate layers at the Straits of th e Cretan Arc, while the deep regime seems rather constant. Topographic cont rol is evident on the flows through the straits. The new very dense deep wa ter mass, namely the Cretan Deep Water (CDW) and a well-defined intermediat e layer of minimum temperature and salinity, the so-called Transition Medit erranean Water (TMW), consists the new important structural elements of the South Aegean Sea. The CDW outflows towards the deep and bottom layers of t he Eastern Mediterranean, thus considerably contributing to the formation o f the new, denser Deep and Bottom Water of the Eastern Mediterranean, which sinks and displaces the Eastern Mediterranean Deep Water of Adriatic origi n in the adjacent sea regions outside the Aegean Sea. (C) 2000 Elsevier Sci ence Ltd. All rights reserved.