Mesoscale circulation in the Black Sea : a study combining numerical modelling and observations

Abstract

Mesoscale dynamics play a major role in the general circulation throughout the ocean. Mesoscale eddies promote the exchange of material and physical properties between different areas of the ocean such as continental shelves and the deep seas. Despite the increasing number of studies on mesoscale processes, there are further important questions unanswered concerning the origin and evolution of eddies, the mechanisms enhancing mesoscale activity and the detachment of eddies from the coast. The present research contributes to the understanding of the mesoscale circulation in the Black Sea basin by combining hydrodynamic numerical modelling with observational data analysis. Within this research: i) A folly working eddy resolving Black Sea model was set up using the POLCOMS 3-D numerical code, ii) The mesoscale circulation in the Black Sea during October-November 2004 was characterised from in situ CTD measurements and from satellite-derived sea surface temperature data, iii) The Black Sea model was tested and validated against observational data, iv) The model was used to simulate the Black Sea hydrodynamics and to investigate the effects of the variability of the wind on the mesoscale activity of the basin. The detailed spatial and temporal variability of the wind field was included in the model forcing by using NCEP re-analysis wind data.