The Interannual and Seasonal Variability of the MAW and LIW Core Properties in the Western Mediterranean Sea

Historical in situ temperature and salinity data for the period 1950-1987 are examined to studythe seasonal and interannual variability of the core properties of Modified Atlantic Water (MAW) and Levantine Intermediate Water (LIW) in the Western Mediterranean Sea. The seasonal cycle is well detected in the MAW core temperature but not in the salinity. The seasonal differences between the MAW/LIW cores indicate that at basin scale, the maximum MAW/LIW mixing occursin winter, when Garrett et al. (1990) deduced a tendency to overmixing conditions in the Western Mediterranean. The data show a definite interannual increase in the LIW core temperature and salinity during the nearly 40 years of data. This may be due to regional or global climatic changes or decreases in river runoff in the eastern Mediterranean.