The Role of the Bottom Relief and the β-effect in the Black Sea Dynamics

A. A. Pavlushin✉, N. B. Shapiro, E. N. Mikhailova

Marine Hydrophysical Institute, Russian Academy of Sciences, Sevastopol, Russian Federation

✉ e-mail: pavlushin@mhi-ras.ru

Abstract

The results of the numerical experiments carried out within the two-layer eddy-resolving Black Sea model are discussed. The motion of the liquid is excited by a stationary wind with a constant cyclonic vorticity. Bottom relief, β-effect, bottom friction and horizontal turbulent viscosity parameterized by the bi-harmonic operator are taken into account in the model. Friction on the interface of the layers is not taken into account, thus, the motion in the lower layer is excited only by non-linear factors. The calculations cover a long period (20 years) up to the moment when the solution achieves the statistically equilibrium mode which is characterized by presence of intense currents, waves and eddies. It is shown that under the statistically equilibrium mode, a cyclonic circulation is formed in the sea: in the upper layer – a meandering flow (the Rim Current analog); in the lower layer – rather intensive waves which are imposed on the flow propagating along the isobaths. These waves can be characterized as the topographic Rossby waves trapped by the continental slope. The technique for analyzing such waves is proposed. It is shown that the current wave disturbances in the lower layer significantly influence the flows in the upper layer contributing to their instability and meandering.

Keywords

the Black Sea, eddy resolving model, numerical experiment, β-effect, topographic Rossby waves, bottom relief, trapped waves

For citation

Pavlushin, A.A., Shapiro, N.B. and Mikhailova, E.N., 2017. The Role of the Bottom Relief and the β-effect in the Black Sea Dynamics. Physical Oceanography, (6), pp. 24-35. doi:10.22449/1573-160X-2017-6-24-35

DOI

10.22449/1573-160X-2017-6-24-35

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