Generation of seiches by moving baric formations

Abstract

We consider a plane problem of generation of barotropic seiches in the case of motion of a region of disturbances of atmospheric pressure over a bounded basin. The nonlinear system of equations of long waves with regard for the quadratic dependence of bottom friction is solved by the finite-difference method. The calculations are carried out for three basins of variable depth corresponding to rectangular sections of the Black Sea and Sea of Azov. It is shown that the passage of the baric anomaly over the basin is accompanied by the generation of the lowest seiches. The oscillations of fluid are especially intense in the shallow-water zones of the basins. Seiches exhibit a trend to intensification as the velocity of motion of the atmospheric disturbance increases. The dependence on the width of the baric anomaly is not monotonic. In the shelf zone, the amplitude of oscillations of the level can be several times higher that the pure hydrostatic response of the sea surface. In the analyzed basins, the influence of nonlinearity on the seiches is weak.