INVESTIGATING MESOSCALE PHYSICAL PROCESSES FOR VERTICAL AND HORIZONTAL TRANSPORT IN THE BLACK SEA WITH THE IMPLEMENTATION OF A HIGH-RESOLUTION CIRCULATION MODEL

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2019-9-24
Sadighrad, Ehsan
A three-dimensional, high resolution ocean model, the Nucleus for a European Model of the Ocean (NEMO) is set up for the Black Sea. It is used to simulate the general circulation of the Black Sea and investigate interannual variability of physical properties, dynamics and mesoscale features from 1985 to 2014. The model is validated by univariate and multivariate analyses, comparing the model results with available in situ and satellite data of sea surface temperature, salinity and sea surface height. The simulation of mesoscale eddies in the model is compared to eddies detected from satellite sea surface height data using an eddy statistics analysis. The relationship between wind, kinetic energy and current dynamics is studied to investigate variability in the simulated physical properties and upper layer dynamics. The main aim of thesis research is to investigate the impact of horizontal and vertical transport of water masses from the continental shelf to the basin interior and the exchange in the vertical dimension. Results show that mid-winter is the time of maximum kinetic energy transfer from atmosphere to the ocean. Then a strong Rim Current with maximum eastward transport dominates the circulation. In this time strong vertical, upwelling velocities are observed in the Rim Current and eddies. In late winter and early spring the weakening of wind results in a decrease of kinetic energy and the following generation of mesoscale eddies enhances onshore-offshore exchange. When kinetic energy reaches its minimum in summer, the number of eddies increase but they are not energetic enough to facilitate strong onshore-offshore water exchange. Vertical transport of water masses and hence nutrients rely on kinetic energy transferred from the atmosphere to the ocean. Larger vertical velocities are observed in winter and early spring as a result of deep mixing and upwelling processes. Vertical velocities are reduced in late spring and summer when kinetic energy is minimum.

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Citation Formats
E. Sadighrad, “INVESTIGATING MESOSCALE PHYSICAL PROCESSES FOR VERTICAL AND HORIZONTAL TRANSPORT IN THE BLACK SEA WITH THE IMPLEMENTATION OF A HIGH-RESOLUTION CIRCULATION MODEL,” M.S. - Master of Science, Middle East Technical University, 2019.