## Studies of Free Fluctuations of the Sea of Azov Level Arising After the Termination of Prolonged Wind Effect

*V.A. Ivanov, L.V. Cherkesov, T.Ya. Shul’ga ^{✉}*

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

^{✉} e-mail: shulgaty@mail.ru

### Abstract

Physical regularities of liquid free fluctuations in the Sea of Azov arising after constant wind has stopped, are analyzed. The simulations are done by a nonlinear three-dimensional sigma-coordinate model. Its application permits to define spatial characteristics of seiche-like fluctuations, arrangement of nodal lines and velocities of the arising currents. The seiche-like fluctuations’ amplitudes and periods are studied for the stations located on the coast and the points of the Azov Sea deep central part. The performed studies result in revealing the fact that the maximum seiche-like oscillations in the coastal zone are comparable to the scales of a storm surge phenomena. At that the level the free fluctuations’ heights in the open sea makes 50 – 89% of those along the coastline. The amplitude of the sea level free oscillations in the deep sea is by 1.2 – 2 times smaller than those at the coastal stations. The results of the numerical experiments testify to the fact that free fluctuations attenuate faster in the central part of the sea than in the coastal regions. Being effected by a stable wind, the sea level changes in the Sea of Azov coastal regions twice exceed the maximum values of the level deviations in the sea central part. In the central part at seiche-like fluctuations, the currents’ maximum velocities exceed the velocities of the gale-induced stationary currents by 21%. It is found that the seiches make essential contribution to variability of the currents’ velocities. At that the level free fluctuations attenuate faster than the amplitudes of currents’ velocities..

### Keywords

three-dimensional nonlinear model, free fluctuations of liquid, seiche, stationary currents, surge phenomena processes, nodal lines

### For citation

Ivanov, V.A., Cherkesov, L.V. and Shul’ga, T.Ya., 2015. Studies of Free Fluctuations of the Sea of Azov Level Arising After the Termination of Prolonged Wind Effect. *Physical Oceanography*, (2), pp. 14-23. doi:10.22449/1573-160X-2015-2-14-23

### DOI

10.22449/1573-160X-2015-2-14-23

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