On the vortical motions in the Black Sea obtained by the 3-D hydrothermodynamical numerical model

Abstract

Abstract. Some results of simulation of the Black Sea circulation with consideration of forcing of different averaged wind types by using 3-D prognostic baroclinic model are presented. The results allow us to consider all depth of the sea basin consisting of some relatively homogeneous sub-layers. Within each of them general circulation processes practically do not change by depth, but essentially change from layer to layer. Such character of changeability interpreted by us as a steepness of the Black Sea general circulation takes place in majority cases of climatic atmospheric wind forcing. In the present paper results are analyzed on an example of forcing of January atmospheric cyclonic vortex with ~250 km diameter. Under such forcing the Ekman surface layer of ~12 m thickness is created. The cyclonic vortex formed in the east part of the Black Sea, which is Taylor-Proudman potential vortex with vertical cylindrical configuration, is described in detail. The vertical distribution of vortex characteristics are given in figures: Brunt-Väisälä frequency and Richardson number taken near the vortex wall with maximal velocity. The viable vortexes are characterized by introduced the universal Reynolds number Re•.

Numerical Study of Variability of Hydrological Regime for the Southeastern Part of the Black Sea (2010-2021)

“…There is a hypothesis of the direct impact of the wind associated with negative wind vorticity over the southeastern region, but there are also other hypotheses [23]. Numerical study carried out in [27] using the basin-scale model of Black Sea dynamics [16,17] with different climate data shows that thermohaline conditions are a very important factor in the generation of the Batumi eddy.…”

“…A high-resolution RM-IG is developed on the basis of the basin-scale model of the Black Sea dynamics [16,17], adapted to the southeastern part of the Black Sea, and is based on a full system of ocean hydrothermodynamics equations written in Cartesian coordinate system for deviations of temperature, salinity, pressure and density from corresponding standard vertical distributions. The RM-IG takes into account: 1.…”

Numerical study of the circulation and its contribution to the oil slick transport in the southeastern part of the Black Sea

“…The high-resolution RM-IG is received by adaptation of the basin-scale model of the Black Sea(Demetrashvili et al 2008; Kordzadze and Demetrashvili 2008; Kvaratskhelia et al 2021) to the physical and geographical conditions of the southeastern part, which covers Georgian sector of the Black Sea and surrounding water area bounded between 40.8 0 N -44.09 0 N and 39.07 0 E -41.8 0 E. In its turn, the basinscale model is advanced version of the model by Marchuk et al (1975). The RM-IG is a z-level hydrostatic model with 1 km horizontal spatial resolution based on the solution of a primitive system of ocean hydro and thermodynamics equations, which is nested in the basin-scale model (BSM) of the Black Sea dynamics with 5 km spatial resolution of the Marine Hydrophysical Institute (MHI, Sevastopol, Ukraine) within the EC project ARENA (2003-2005) (Kordzadze and Demetrashvili 2011, 2017; Demetrashvili and Kukhalashvili 2019; Demetrashvili et al 2022b).…”

Operational forecast of hydrophysical fields in the Georgian Black Sea coastal zone within the ECOOP

“…The main component of the regional forecasting system (RM-IG) is developed by adaptation of the BSM of the Black Sea dynamics of M. Nodia Institute of Geophysics (Kordzadze and Demetrashvili 2004; Demetrashvili et al, 2008) to the easternmost part of the basin and one-way nesting in the BSM of MHI (without feedback from RM-IG to BSM). It is necessary to note that in turn the BSM of Institute of Geophysics is an improved version of the prognostic model of the Black Sea dynamics (Kordzadze and Skiba, 1973;Marchuk et al, 1975Marchuk et al, , 1979Marchuk and Kordzadze, 1986;Kordzadze, 1989) originally developed in the early 1970s at the Computing Center of Siberian Branch of the Academy of Sciences USSR (Novosibirsk, Akademgorodok).…”