Parameterization of surface wind-driven currents in the Black Sea using drifters, wind, and altimetry data

The study of Black Sea and Mediterranean Sea surface altitudes was carried out based on satellite altimetry data. The model of the Black Sea and Mediterranean Sea surface topography (SST) was build. The comparison of received results with the European quasigeoid was done.

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The use of CMEMS Black Sea Physical Reanalysis (1993-2019) to understand better the Black Sea variability

10.5194/egusphere-egu21-6057 ◽

2021 ◽

Author(s):

Elisaveta Peneva ◽

Leonardo Lima ◽

Ali Aydogdu ◽

Simona Masina ◽

Emil Stanev ◽

...

Keyword(s):

Black Sea ◽

General Circulation ◽

Mixed Layer Depth ◽

Surface Wind ◽

Reanalysis Data ◽

Current Speed ◽

The Black Sea ◽

Positive Trend ◽

Dynamic Feature ◽

Positive Tendency

The recently upgrated CMEMS product Black Sea Physical Reanalysis (BLKSEA_MULTIYEAR_PHY_007_004) covers the period 1993-2019 presenting a base for reliable long-term estimates on different aspects of the Black Sea physical processes. The data archive provides monthly and daily fields for the Black Sea basin including 3D variables (temperature, salinity, zonal and meridional velocity components) and 2D variables (mixed layer depth, bottom temperature and sea surface height).&#160;The good spatial and temporal resolution of the reanalysis gives possibility to evaluate the trend and variability of the subsurface temperature and salinity, as well as the general circulation changes. In the last two decades significant tendency for warming is observed at the surface and in deeper layers, reaching down ~100 m depth. This trend is associated with a slight positive salinity trend seen down to ~200 m depth, which is present almost in the entire Black Sea except for the north-western shelf close to the Danube and Dnestr river delta. Both temperature and salinity show strong interannual variability.&#160;&#160;The calculated Ocean Heat Content (OHC) in the Black Sea basin over the last ~30 year period suggests that the Black Sea water had experienced a general heating tendency after 2013. The increase of OHC is mostly due to the layer 0-200 m and the deeper layers are rather conservative in time. Nevertheless, the cold winter conditions in 2006, 2012 and 2017 led to significant surface water cooling and replenishment of the Cold Intermediate Layer.&#160;The variation in the main dynamic feature of the basin, the Black Sea Rim current, is studied using the reanalysis data. It shows that the surface current speed varies within ~30% in the period 1993-2019 with a slight positive tendency. The main factor which triggers the inter-annual variability of the Rim current is found to be the atmospheric forcing. Comparison with the surface wind curl from the ERA5 reanalysis data shows significant correlation, predominantly positive (cyclonic) curl for both sea and atmosphere circulation and similar positive trend of the wind/current speed. This proves that the Black Sea Rim Current could be considered a Sverdrup balanced flow and thus strongly related to the regional air circulation.

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Assimilation of altimetry data in the numerical model of the circulation in the Black Sea: The model numerical experiments

Physical Oceanography ◽

10.1007/bf02198508 ◽

1994 ◽

Vol 5 (6) ◽

pp. 423-434

Author(s):

V. V. Knysh ◽

V. V. Chernov

Keyword(s):

Numerical Model ◽

Black Sea ◽

Numerical Experiments ◽

The Black Sea ◽

Altimetry Data

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Geostrophic currents and kinetic energies in the Black Sea estimated from merged drifter and satellite altimetry data

Ocean Science ◽

10.5194/os-10-155-2014 ◽

2014 ◽

Vol 10 (2) ◽

pp. 155-165 ◽

Cited By ~ 6

Author(s):

M. Menna ◽

P.-M. Poulain

Keyword(s):

Kinetic Energy ◽

Black Sea ◽

Satellite Altimetry ◽

The Black Sea ◽

Altimetry Data ◽

Data Set ◽

Velocity Statistics ◽

Intense Activity ◽

Surface Geostrophic Circulation ◽

Satellite Altimetry Data

Abstract. Drifter measurements and satellite altimetry data are merged to reconstruct the surface geostrophic circulation of the Black Sea in the period 1999–2009. This combined data set is used to estimate pseudo-Eulerian velocity statistics for different time periods. Seasonal and interannual variability of currents and kinetic energy fields are described with particular attention to the mesoscale and sub-basin coastal eddies. The mean currents are generally stronger in winter and enhanced speeds are observed in the period 2002–2006. The most intense activity of sub-basin Batumi Eddy occurs in summer with greater speeds and dimensions in 2006 and 2008. The sub-basin Sevastopol Eddy is generated in spring from a meander of the Rim Current. Mesoscale eddies located along the Anatolia, Caucasus and Crimea coasts are permanent, quasi-permanent or intermittent features and can interact and merge with each other, showing high values of kinetic energy.

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Influence of increasing sea surface temperature on the mussel recruitment off the southwestern coast of Crimea

Monitoring systems of environment ◽

10.33075/2220-5861-2020-3-133-138 ◽

2020 ◽

pp. 133-138

Author(s):

I.I. Kazankova ◽

Keyword(s):

Surface Layer ◽

Surface Water ◽

Water Temperature ◽

Black Sea ◽

Surface Wind ◽

Reproductive Potential ◽

The Black Sea ◽

Ecological Change ◽

Maximum Increase ◽

Average Annual Temperature

The article discusses the possibility of a connection between an increase in the temperature of the surface layer of water and a decrease in the potential replenishment of the Black Sea population of the mussel Mytilus galloprovincialis recruitment off the southwestern coast of Crimea in recent decades. The considered biological parameter is characterized by the number of mussel post-larvae, formed planktonic larvae that settled on the experimental substrate per unit of time (usually a month). The study of water temperature variability in the region showed that from the 80s of the last century to the present, there has been an increase in the average annual temperature of the surface water layer by about 2 ° C. The maximum increase in water temperature was noted during the warm period of the year, especially in June, July and September – during these months it was about 5°C. This ecological change took place against the background and, very likely, due to the previously noted processes of global warming, freshening of the surface layer of the Black Sea, a decrease in its vertical mixing, a decrease in the frequency and duration of coastal upwellings, and an increase in the eastern component in the surface wind speed in the region, contributing to the intensification of surge phenomena off the coast of Crimea. All these processes can lead to a decrease in the productivity of the surface layer of the sea, and, consequently, in the reproductive potential of the mussel population, as well as to a decrease in the probability of its larvae appearing in mass number at the stage of settling in the coastal zone during upwellings. In addition, a significant increase in the temperature of surface water in the Black Sea in the warm season can contribute to the food and reproductive activity of the predatory Rapana, feeding mainly on mussels, as well as to the survival of its juveniles. Thus, an increase in the temperature of the surface layer of the sea and the processes leading to this increase can directly or indirectly contribute to a decrease in the potential recruitment replenishment of the mussel and a decrease in reproduction of its population in the Black Sea.

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

Ocean Science Discussions ◽

10.5194/osd-8-397-2011 ◽

2011 ◽

Vol 8 (1) ◽

pp. 397-433 ◽

Cited By ~ 1

Author(s):

A. A. Kordzadze ◽

D. I. Demetrashvili

Keyword(s):

High Resolution ◽

Black Sea ◽

Surface Wind ◽

Scale Model ◽

The Black Sea ◽

Time Step ◽

Regional Area ◽

Study Results ◽

Basin Scale ◽

Forecasting System

Abstract. One of the part of the Black Sea Nowcasting/Forecasting System is the regional forecasting system for the Easternmost part of the Black Sea (including the Georgian water area), which have been developed within the context of the EU International projects ARENA and ECOOP. A core of the regional system is a high-resolution baroclinic regional model of the Black Sea dynamics developed at M. Nodia Institute of Geophysics (RM-IG). This model is nested in the basin-scale model (BSM) of Marine Hydrophysical Institute (MHI, Sevastopol/Ukraine). The regional area is limited to the Caucasian and Turkish coastal lines and the western liquid boundary coinciding with a meridian 39.36° E. Since June 2010 we regularly compute 3 days' forecasts of current, temperature and salinity for the Easternmost part of the Black Sea with 1 km spacing. In this study results of two forecasts are presented. The first forecast corresponds to Summer season and covers the prognostic interval from 00:00 h, 6 August to 00:00 h, 9 August 2010. The second one corresponds to Autumn season and covers the prognostic interval from 00:00 h, 26 October to 00:00 h, 29 October 2010. Data needed for the forecasts – the 3-D initial and prognostic hydrophysical fields, also 2-D prognostic meteorological fields at the sea surface, wind stress, heat fluxes, evaporation and precipitation rates for the our regional area are placing on the MHI server every day and we are available to use these data operatively. Prognostic hydrophysical fields are results of forecast by BSM of MHI and 2-D meteorological boundary fields represent results of forecast by regional atmospheric model ALADIN. All these fields are given on the grid of BSM with 5 km spacing and with one-hour time step frequency for the integration period. The analysis of predicted fields shows that to use the model with high resolution is very important factor for identification of nearshore eddies of small sizes. It should be noted very different character of regional circulation in summer and autumn seasons in the Easternmost part of the Black Sea.

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