SEA ME

Working group Experimental Oceanography

SEA ME - Shifts in the Eastern Mediterranean Hydrography and Circulation observed on repeated transects through the Mediterranean Sea

The thermohaline circulation of the Mediterranean Sea is complex and undergoes similar processes like those characterizing the thermohaline circulation of the global ocean. It is divided into a primary open circulation cell covering the whole Mediterranean Sea and two closed cells affecting the western respectively the eastern basins of the Mediterranean.

The open cell is mainly characterized by inflowing Atlantic water at the surface and by returning flow in the intermediate layer. This saline intermediate water mass is called Levantine Intermediate Water due to is production area, the Levantine basin and it is the major contributor to the saline and warm outflow into the Atlantic.

The closed cells affect the deep layers of the basins and are driven by local convection (Gulf of Lion for the western Mediterranean, Adriatic and Aegean Sea for the eastern Mediterranean) leading to the formation of deep and bottom water masses.  

The purpose of this project is to investigate two hydrographic processes in the Mediterranean Sea:

a) To determine long term variations of the Levantine Intermediate Water, the salinity of which not only influences the global circulation of the Mediterranean Sea but also contributes to the salinity distribution of the northern Atlantic in intermediate depths up to the coast of America and which can therefore be relevant for the ocean’s climate.

b) To investigate the deep water masses of the Eastern Mediterranean Sea. In the Eastern Mediterranean Sea drastic changes in the hydrography and circulation occurred during the last decades, which are known as the Eastern Mediterranean Transient (EMT). One phenomenon of the EMT was the shift of deep water formation from the Adriatic Sea to the Aegean Sea. The impacts of the EMT are still noticeable and result in an ongoing changing thermohaline circulation.

Dagmar Hainbucher, Detlef Quadfasel