Alekseev D. The Numerical Simulation of the Non-steady-state Currents, Admixture and Suspension Transport on the North-West Shelf of the Black Sea

The Thesis is dedicated to the numerical simulation of dynamical processes caused by atmospheric cyclones on the north-west shelf of the Black Sea. For the first time in the storm conditions structure of non-steady-state currents is studied and theirs effect on the advection-diffusion of pollution and forming of suspended fine sediment concentration fields is estimated. Two- and three-dimensional numerical models adapted to the Black Sea region are used. In the framework of the two-dimensional model dependences of transport directions of pollution areas and dissipation rate of admixture on trajectories of cyclones are studied. On the basis of three-dimensional barotropic model evolution of velocity fields of non-steady-state currents and sea level is considered with high space resolution due to the use of nested-grid technique. Dependences of transport direction, penetration depth and dissipation time of pollution on eddy diffusion intensity and local peculiarities of current field in the occurrences of the momentary or permanent sources are studied. The areas of bottom erosion during the passing of cyclones and ones of deposition of suspended sediments are obtained. The relation of structure of suspension concentration fields with the location of erosion areas is found.