NUMERICAL STUDIES OF THE MATTER TRANSFER IN THE THERMAIKOS GULF

摘要

This work aims toward the numerical modelling of the processes that govern the transport of matter in Thermaikos Gulf (NW Aegean Sea, Eastern Mediterranean) across the interface between the low-salinity coastal waters of river origin and the higher salinity basin waters. Of particular importance is the overall basin general circulation, which is influenced by coastal dynamics and the interaction with larger scale Aegean flows; the interaction between land and sea, which takes the form of studies in plume dynamics; the air-sea interaction; and the sedimentation processes that determine the rates and pathways of sediment particles, as well as the location of their final deposition. A comprehensive hydrodynamic model was developed for Thermaikos, which is further used to perform realistic simulations with high frequency forcing. The hydrodynamic model was extended to include sedimentation processes and the physical and sediment transport processes that influence matter transfer on the gulf were studied. The important physical processes, namely the wind stress, buoyancy due to river input, topographic effects and interaction with deeper Aegean Sea flows were elucidated in time scales from a few days to seasonal. The sediment transport processes included advection and diffusion, deposition and erosion, flocculation and settling. The effects of the different processes on the transfer of river-borne low salinity waters and fine grain particles, were examined separately and combined, so that their significance was made clear.