On the summer mesoscale variability of the Black Sea

2001-07-01
Besiktepe, ST
Lozano, CJ
Robinson, AR
The evolution of the Black Sea temperature, salinity and circulation, from large scale to mesoscale, is studied using a data-driven primitive equation simulation. The data are drawn from (i) a basin-wide hydrographic survey, CoMSBlack'92, obtained in the Summer of 1992; (ii) wind stress derived from wind analyses of the Sevastopol MSIA/URHI Office; (iii) climatological heat fluxes; and (iv) climatological river outflows. The primitive equation model is from the Harvard Ocean Prediction System. The simulation is used to examine the evolution of the circulation at mesoscale resolution, its dominant variabilities and dependencies in the summer period. The large-scale upper layer circulation over the deep portion of the basin is generally cyclonic with a system of anticyclonic eddies evolving in its periphery. The edge of the cyclonic circulation is dominated by an inertial jet: the Rim Current. As the Rim Current transverses the edge of the deep basin, the meandering and secondary circulation associated to the jet varies according to internal dynamics and interactions with the bottom topography and shelf water circulation. The relatively broad northwestern shelf is found to be mostly wind driven with a buoyancy-driven coastal current and interacting with the quasi-stationary Crimea and Kaliakra anticyclones. The seasonal thermocline is strengthened during this period and a zonal large-scale temperature gradient with warmer/colder sea-surface temperatures in the east/west is driven by the observed weak/strong winds. Some of the major circulation elements are partially verified using qualitative comparisons with the Summer of 1992 data and historical data; both in situ, and infrared and color remotely sensed data. The Rim Current meander shape and propagation parameters, eddy size and distribution, and the generation of rapid surface bound jets are found to be in good agreement with observations. The simulation shows two previously unobserved events: an anticyclonic eddy is shed near Sinop; and the anticyclones moving north along the Caucasian coast are formed and shed from the Batumi eddy. Imprint, of these events are found in the historical record.
JOURNAL OF MARINE RESEARCH

Suggestions

Extension of sea surface temperature unpredictability
Akhmet, Marat; Alejaily, Ejaily Milad (Springer Science and Business Media LLC, 2019-02-01)
The sea surface temperature (SST) variability is clearly affected by global climate patterns, which involve large-scale ocean-atmosphere fluctuations similar to the El Nino-Southern Oscillation (ENSO). We give mathematical arguments for the SST to be unpredictable over oceans. Sensitivity (unpredictability) is the core ingredient of chaos. Several researches suggested that the ENSO might be chaotic. It was Vallis (Science 232:243-245, 1986) who revealed unpredictability in ENSO by reducing his model to the ...
Intermediate and deep currents of the Black Sea, obtained from autonomous profiling floats
Korotaev, G.; Oguz, T.; Riser, S. (Elsevier BV, 2006-01-01)
Float trajectories observed at three depths (200, 750 and 1550m) in the Black Sea during a 1.5-yr period offer new insights on the circulation below the permanent pycnocline. The float observations for the first time provided direct, quantitative evidence for strong currents and a well-organized flow structure at intermediate and deep layers, in contrast to prior ideas of a rather sluggish deep circulation of the Black Sea. The magnitudes of intermediate and deep currents are typically about 5-10% of the su...
A 2-LAYER MODEL OF WATER EXCHANGE THROUGH THE DARDANELLES STRAIT
OGUZ, T; SUR, HI (1989-01-01)
Water exchange through the Dardanelles Strait is studied by a two-layer model which considers the laterally averaged flow formed by two homogeneous layers of differing density separated by an entraining interface. The model response is discussed in terms of observations from the strait. In particular, the observed asymmetry and rapid transition at the interface depth as weil as the intense mixing which occurs in the southwestern reaches of the strait are found to be related to the hydraulic characteristics ...
Carbon and nitrogen isotopic ratios of suspended particulate organic matter (SPOM) in the Black Sea water column
Coban-Yildiz, Yesim; Altabet, M; YILMAZ, AYŞEN; Tuğrul, Süleyman (Elsevier BV, 2006-01-01)
Carbon and nitrogen isotopic ratios (delta(13)N and delta(13)C) of suspended particulate organic matter (SPOM) in the water column of the Black Sea were measured at a total of nine stations in September-October (autumn) 1999 and May 2001. For comparison, a station in the Mediterranean Sea and one in the Sea of Marmara were sampled in October 1999. Large-sized particle samples, as well as samples of surface sediment were also collected for N and C isotopic analysis. The results revealed important vertical an...
A SYNTHESIS OF THE LEVANTINE BASIN CIRCULATION AND HYDROGRAPHY, 1985-1990
OZSOY, E; HECHT, A; UNLUATA, U; BRENNER, S; SUR, HI; BISHOP, J; LATIF, MA; ROZENTRAUB, Z; OGUZ, T (Elsevier BV, 1993-01-01)
The Levantine Basin circulation derived from recent data consists of a series of sub-basin-scale to mesoscale eddies interconnected by jets. The basin-scale circulation is masked by eddy variability that modulates and modifies it on seasonal and interannual time scales. Long-term qualitative changes in the circulation are reflected in the bifurcation patterns of the mid-basin jets, relative strengths of eddies and the hydrographic properties at the core of these eddies. Confinement within the Basin geometry...
Citation Formats
S. Besiktepe, C. Lozano, and A. Robinson, “On the summer mesoscale variability of the Black Sea,” JOURNAL OF MARINE RESEARCH, pp. 475–515, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/66410.