Water Masses in the Eastern Mediterranean Sea: An Analysis of Measured Isotopic Oxygen

We investigate aspects of the water mass structure of the Adriatic and Ionian basins (Eastern Mediterranean Sea) and their interdecadal variability through statistical analyses focused on δ18O measurements carried out in 1985, 1990, and 2011. In particular, the more recent δ18O measurements extend throughout the entire water column and constitute, to the best of our knowledge, the largest synoptic dataset encompassing different sub-basins of the Mediterranean Sea. We study the statistical linkages between temperature, salinity, dissolved oxygen and δ18O. We find that δ18O is largely independent from the other parameters, and it can be used to trace major water masses that are typically found in the basins, including the Adriatic Dense Water, the Levantine Intermediate Water, and the Cretan Intermediate and Dense Waters. Finally, we explore the possibility of using δ18O concentration as a proxy for dominant modes of large-scale oceanic variability in the Mediterranean Sea.