Nonhydrostatic model of marine circulation

A nonhydrostatic sigma-model of marine dynamics is presented. A numerical algorithm for solving the problem based on the method of splitting with respect to the physical processes and geometric coordinates is described. The splitting method allows the construction of an efficient numerical model, which is a natural improvement of the input model based on the primitive equations. The model is tested in a series of calculations of marine dynamics in a rectangular sea (academic) basin. The academic basin approximates the middle part of the Baltic Sea. The results of numerical calculations for different (low and high) horizontal resolutions of the model in the hydrostatic and nonhydrostatic approximations are described. To illustrate the model adequacy, the results of the calculation of the Gulf of Finland dynamics are presented.