статья в журнале

En

Izvestiya - Atmospheric and Ocean Physics

ISSN:00014338

2023

10.1134/S0001433823050043

Abstract: An analysis of the dynamic and energy characteristics of water circulation in the northern part of the Black Sea has been performed on the basis of assimilation in the numerical model of the data of three hydrological surveys in 2016, carried out on expeditions of 87, 89, and 91 cruises of the R/V Professor Vodyanitsky (summer, autumn, and autumn–winter seasons). Numerical experiments are implemented on a horizontal grid (~1.6 × ~1.6 km) with 27 vertical horizons and an atmospheric effect close to the real one was used. A procedure of assimilation of the observational data is based on the Kalman filter, taking into account the heterogeneity and nonisotropy of the errors of the estimates of the temperature and salinity fields. The integral energy terms in the kinetic and potential energy budget equations for three seasons are estimated. In the summer season, there is a slight weakening of the main Black Sea current—the Rim Current (RC)—and the main mechanism for the formation of anticyclonic eddies near Sevastopol and near the southeastern shores of Crimea is baroclinic instability of the current (as evidenced by the increase in the slope of isopycnical surfaces and negative values of the work of the buoyancy force). An anticyclonic eddy near Yalta with a radius of about 25 km was generated due to the development of shear instability of the current. In the autumn season, the RC jet is pressed to the shore and there is a decrease in the number of eddies in comparison with the summer season. The formation of anticyclonic eddies with a radius of about 35–40 km in the western part of the region is caused by barotropic instability of the current and the formation of eddies along the Crimean coast is caused by baroclinic instability. In the autumn–winter season, the RC has a pronounced jet character and there is an increase in the processes of baroclinic instability with the generation of eddies of different scales between the coast and the RC, as well as in the area located between 31.5 and 33° E, with the weakening of the wind effect. During all seasons, small-scale anticyclonic and cyclonic eddies could be generated along the western and eastern coast of Crimea in the upper layer when the current flows around the coastline and inhomogeneities of the bottom topography under the action of weak winds. © 2023, Pleiades Publishing, Ltd.

Black Sea, high spatial resolution, mesoscale and submesoscale eddies, numerical modeling, observational data assimilation

2023-11-15 11:57:59