The upper layer circulation of the Black Sea: Its variability as inferred from hydrographic and satellite observations

Abstract

Quasi-synoptic hydrographic data and satellite imagery are used to describe the circulation and the structural variability of the Black Sea with particular emphasis on the Turkish coast. The circulation is indicated to involve a variable cyclonic circulation with no apparent central locus and a well-defined cyclonic "Rim Current" containing meanders and interacting eddy fields confined to the shelf slope. Interspersed between the coastal eddies are filaments and intense jets, often with dipole eddies at their termina. The extension of these features across the shelf-slope into the central basin offshore waters implies important dynamical processes related to the shelf-deep basin exchanges. These features are often steered by the topography and evolve continuously through the mixed baroclinic-barotropic instability of the Rim Current.

Small river plumes off the northeastern coast of the Black Sea under average climatic and flooding discharge conditions

“…The main large-scale and mesoscale circulation features described in Sect. 2.3 were adequately reproduced by numerical model- ing, including the Black Sea Rim Current, the three quasistationary cyclonic gyres at the central divergence zone, and the four quasi-stationary anticyclonic gyres at the eastern part of the Black Sea near Sebastopol, Kerch, Batumi, and Gelendzhik (Oguz et al, 1992(Oguz et al, , 1993(Oguz et al, , 1995Stanev, 1995;Staneva et al, 2001). These features are visible in Fig.…”

“…7, which shows the modeled Black Sea current field at a depth of 10 m projected on a uniform grid with 10 km spatial resolution and averaged for June 2011. The model also reproduced seasonal variations of sea surface circulation, in particular winter-spring intensification of the Rim Current, meandering of the main flow of the Rim Current caused by baroclinic instability, and formation of multiple nearshore anticyclonic eddies during summer at the eastern part of the Black Sea (Oguz et al, 1992(Oguz et al, , 1993Titov, 2002;Zatsepin et al, 2003;Enriquez et al, 2005). The simulated main flow of the Rim Current shifts offshore (approximately 45 km) in June and its speed decreases to 20 cm s −1 (Fig.…”

“…General water transport of the Black Sea is governed by a current system cyclonically circulating along the continental slope, which is generally referred to as the Black Sea Rim Current (e.g., Oguz et al, 1992Oguz et al, , 1993Kortotaev et al, 2003). The velocity of the Rim Current at the northeastern part of the Black Sea is 0.2-0.5 m s −1 .…”

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“…Attraction of new technologies of observations including satellite methods of measurement and progress of computer facilities providing creation of highly resolving numerical models allowing to reproduce sea processes by sufficiently high adequacy promoted better understanding of physical and biogeochemical processes in the Black Sea (Oguz et al, 1992;Oguz and Besiktepe, 1999;Stanev, 2005;Korotaev and Eremeev, 2006;Salihoglu et al, 2011;Oguz et al, 2012). Especially the large scientific and technical achievement of the Black Sea operative oceanography is the development of the Black Sea Nowcasting/Forecasting System which allows to carry out continuous control over the current state of the Black Sea and its change for some days forward (Besiktepe, 2003a(Besiktepe, , 2003bKubryakov et al, 2006;Korotaev et al, , 2011Kordzadze and Demetrashvili, 2010).…”

Simulation of eddy‐driven phytoplankton production in the Black Sea

“…The boundary flow system, named the Rim Current, exhibits a narrow and pronounced frontal structure between the less saline/less dense coastal waters and saltier/colder interior waters. This system is accompanied by intense mesoscale activity such as filaments, squirts and mushroom eddies [Oguz et at., 1992[Oguz et at., , 1994 A three dimensional, three layer biological model is developed to interpret these observations on a more quantitative ground, and to elaborate our present understanding of the role of mesoscale dominated circulation on the Black Sea pelagic ecosystem. The present paper describes an idealized process-oriented study demonstrating how a typical eddy-dominated circulation system can lead to a temporally 1Now graduate student at Center for Coastal Oceanogra- The model is integrated for four years, in which all the biological fields reach an equilibrium state.…”