Heat and salt content changes in the Adriatic Sea in response to observed variations of the thermohaline circulation in the Eastern Mediterranean

During the past 20 years, important changes have been observed in the Eastern Mediterranean. The most important concerns the transient event related to the dense water production that shifted from the Adriatic into the Aegean Sea between 1987 and 1995 [1]. This event has been largely attributed to an increase of salinity and to anomalies in the air-sea heat and freshwater fluxes occurring in the Aegean Sea at the beginning of the 90’s [2]. Basin-wide hydrographic observations conducted in the Eastern Mediterranean during the last decade (1995-2002) attest the status and the evolution of the major transient event showing a dumping of the deep Aegean outflow [3] and the presence of an additional source of highly saline and warm intermediate water that flows from the Cretan Sea (Southern Aegean) into the Ionian Sea, propagating prevalently into the Adriatic Sea [4]. Moreover, the presence of transitional layer (i.e. between the intermediate and the deep layers), mostly occupied by the old deep water, makes more separated the upper and the deep circulations, inhibiting the vertical mixing and favouring the spreading of the Levantine Intermediate Water.