Eastern Mediterranean Sea spatial and temporal variability of thermohaline structure and circulation identified from observational (T, S) profiles

Abstract

In this thesis, the optimal spectral decomposition (OSD) method was used to establish the synoptic monthly varying three-dimensional gridded temperature and salinity data for 54 years on a 0.25°x0.25° grid. The analysis included 164,906 temperature profiles and 53,606 salinity profiles. After the establishment of gridded data, the seasonal and inter-annual variability of thermohaline structure and circulation were investigated. Surface depth shows high seasonal temperature variability through the year. There is almost no seasonal salinity variability in winter and spring seasons, while the summer and fall seasons show slight seasonal variation in the surface depth. P-vector inverse method is used to obtain the sea surface absolute geostrophic velocity. In EOF analyses, intermediate layer heat content anomaly is larger than the surface layer. However, inter-annual variability of heat content anomaly in the deep layer is very weak. Deep layer and intermediate layer show similar freshwater content anomalies, and both of them are larger than the surface layer.