Water Mass Variability and Levantine Intermediate Water Formation in the Eastern Mediterranean Between 2015 and 2017

Abstract

AbstractThe physical characteristics of water masses in the Cilician Basin were analyzed based on recent, comprehensive in‐situ data. Nine seasonal cruises from June 2015 to November 2017 were carried out in an area located in the north‐eastern Levantine Basin between the coasts of Turkey and Cyprus. In this little studied area, the structure of the water column, its seasonal variability, and water formation events are investigated. The extensive data set reveals that in summer Modified Atlantic Water (MAW) is observed at about 50 m depth. Saltier and warmer Levantine Intermediate Water (LIW) lies below the MAW between ∼100 and 250 m. During winter, the water column becomes mixed due to surface cooling and vertical convection, and displays uniform properties from the surface to about 200–300 m depths. The yearly cycle of a vertically uniform water column during winter and the appearance of LIW in the following period suggests that LIW is being formed in this region, which is confirmed through heat and buoyancy flux calculations. It is the first time LIW formation is reported in this area of the north‐eastern Levantine Basin and adds to the areas of LIW formation outside Rhodes Gyre. In the 2.5 years of the study, LIW salinity increased by 0.11 psu in 2017, while surface water salinity increased by 0.5 psu over the same period. The presence of meso‐scale eddies in the study area is observed throughout the year. The eddies are short‐lived, having a time span of a few months, during which they either change location or disappear.