The research of the dust transport impact on the biogeochemical characteristics of the Black Sea surface layer

2019 ◽  
Author(s):  
Darya V. Kalinskaya ◽  
Alla Varenik
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Sea Surface ◽  
The Black Sea ◽  
Dust Transport

Role of suspended matter in controlling beryllium-7 (7Be) in the Black Sea surface layer

2021 ◽  
pp. 103513
Author(s):  
Dmitrii A. Kremenchutskii ◽  
Gennady F. Batrakov ◽  
Illarion I. Dovhyi ◽  
Yury A. Sapozhnikov
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Suspended Matter ◽  
Sea Surface ◽  
The Black Sea

scholarly journals The Effect of Dust Transport on the Concentration of Chlorophyll-A in the Surface Layer of the Black Sea

2021 ◽  
Vol 11 (10) ◽  
pp. 4692
Author(s):  
Alla V. Varenik ◽  
Darya V. Kalinskaya
Keyword(s):  
Surface Layer ◽  
Chlorophyll A ◽  
Black Sea ◽  
Inorganic Nitrogen ◽  
Atmospheric Precipitation ◽  
The Black Sea ◽  
Background Concentration ◽  
Dust Transport ◽  
Chlorophyll A Concentration ◽  
Atmospheric Depositions

This paper focuses on the atmospheric dust transport effect on the changes in chlorophyll-A concentration in the Black Sea surface layer. In order to assess the input of nutrients with atmospheric precipitations at the Crimean coast of the Black Sea, the collected samples were analyzed for the content of inorganic nitrogen, phosphates, and silicon. The samples were taken into a wet-only sampler and into a permanently open one, to assess the effect of dust on the nutrients concentration in dry depositions. Cases of multi-fold excess of the nutrients content in the open sampler collected precipitation over that in the wet-only sampler were identified. For such high concentration cases, the 7-day back-trajectories analyses was carried out using the model of the international network AERONET and the HYSPLIT model. The results of our research showed that the influx of nutrients with the atmospheric depositions can result in increasing of chlorophyll-A concentration in 11–36% in the surface layer of the Black Sea. After atmospheric depositions, concentration of phosphates in the surface layer can increase more than five times compared with the background concentration. The increase of silicon concentration can reach 30%. The influx of atmospheric precipitation containing significant amounts of nutrients into the bay can shifts the Redfield ratio compared with background value up to three times.

scholarly journals Дистанционная регистрация следа судна по проявлениям на морской поверхности и приповерхностном слое морской среды и атмосферы

2019 ◽  
Vol 127 (10) ◽  
pp. 616
Author(s):  
В.Н. Носов ◽  
С.Б. Каледин ◽  
С.Г. Иванов ◽  
В.И. Тимонин
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Sea Surface ◽  
The Black Sea ◽  
Natural Conditions ◽  
Near Surface ◽  
Ship Tracks ◽  
Surface Vessel

AbstractThe tracking of hydrodynamic disturbances within the sea surface and near-surface layer and surface layer aerosol is performed using three different installations, a laser locator, photometer of sea brightness, and elastic aerosol lidar. The experiments are carried out under the natural conditions of the Black Sea polygon. A surface vessel was a source of hydrodynamic perturbations in the form of a lagging track. The results reveal the efficiency of the methods used to record ship tracks in three media.

scholarly journals CARBON-TO-CHLOROPHYLL-A RATIO IN THE PHYTOPLANKTON OF THE BLACK SEA SURFACE LAYER: VARIABILITY AND REGULATORY FACTORS

2018 ◽  
Vol 17 ◽  
pp. 60-73 ◽  
Author(s):  
Liudmila V. Stelmakh ◽  
Tatiana I. Gorbunova
Keyword(s):  
Surface Layer ◽  
Surface Water ◽  
Black Sea ◽  
Water Layer ◽  
Taxonomic Composition ◽  
Sea Surface ◽  
The Black Sea ◽  
Summer Period ◽  
Upper Mixed Layer ◽  
Main Influence

Based on the research, conducted in the Black Sea during period of time from 2000 to 2011, seasonal dynamic of C:Chl a ratio and its spatial variability in nano- and microphytoplankton of surface water layer (0–0.5 m) had been analyzed. Maximum values of this parameter were observed in summer, and minimum ones – in winter. Intermediate values of C:Chl a were marked in spring and autumn. The main reasons for variability of the ratio between an organic carbon and chlorophyll a are the light, and different size of phytoplankton and its taxonomic composition. In coastal areas of the sea during summer period, when average values of light intensity in the upper mixed layer are above 20 E·m-2·day-1, size and taxonomic composition of phytoplankton provide main influence to C:Chl a ratio.

scholarly journals Feature of formation of the Black Sea surface layer temperature during air cold intrusions

2019 ◽  
Vol 487 (4) ◽  
pp. 443-447
Author(s):  
A. A. Sizov ◽  
T. M. Bayankina
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Mixed Layer ◽  
Sea Surface ◽  
The Black Sea ◽  
Intermediate Water ◽  
Seasonal Thermocline ◽  
Upper Mixed Layer ◽  
Surface Layer Temperature

Application of the results of the drifter observations performed in the western Black Sea permitted to show that during air cold intrusions (CI) in winter accompanied by the wind (10 m/c and more), the upper mixed layer (UML) was cooled by 0,1-0,2 °C in course of a day. At that the seasonal thermocline (ST) and the cold intermediate water (CIW) sink deeper; after CI is over these layers rise to the depths smaller than their previous ones. It results in decrease of temperature in UML and its increase, as compared to the period preceding CI, in the layer below ST. The process of the sea upper layer mixing is explained by the fact that anti-cyclonic mesoscale vortices are involved in it.

scholarly journals Long term trends in the sea surface temperature of the Black Sea

Ocean Science ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 491-501 ◽  
Author(s):  
G. I. Shapiro ◽  
D. L. Aleynik ◽  
L. D. Mee
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Black Sea ◽  
Sea Surface ◽  
The Black Sea ◽  
The North ◽  
Sst Variability ◽  
Long Term Trends ◽  
Cooling Trend

Abstract. There is growing understanding that recent deterioration of the Black Sea ecosystem was partly due to changes in the marine physical environment. This study uses high resolution 0.25° climatology to analyze sea surface temperature variability over the 20th century in two contrasting regions of the sea. Results show that the deep Black Sea was cooling during the first three quarters of the century and was warming in the last 15–20 years; on aggregate there was a statistically significant cooling trend. The SST variability over the Western shelf was more volatile and it does not show statistically significant trends. The cooling of the deep Black Sea is at variance with the general trend in the North Atlantic and may be related to the decrease of westerly winds over the Black Sea, and a greater influence of the Siberian anticyclone. The timing of the changeover from cooling to warming coincides with the regime shift in the Black Sea ecosystem.

scholarly journals Drivers, mechanisms and long-term variability of seasonal hypoxia on the Black Sea northwestern shelf – is there any recovery after eutrophication?

2013 ◽  
Vol 10 (6) ◽  
pp. 3943-3962 ◽  
Author(s):  
A. Capet ◽  
J.-M. Beckers ◽  
M. Grégoire
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
Interannual Variability ◽  
Black Sea ◽  
Sea Surface ◽  
The Black Sea ◽  
Northwestern Shelf ◽  
Bottom Waters ◽  
Seasonal Hypoxia ◽  
Bottom Hypoxia

Abstract. The Black Sea northwestern shelf (NWS) is a shallow eutrophic area in which the seasonal stratification of the water column isolates the bottom waters from the atmosphere. This prevents ventilation from counterbalancing the large consumption of oxygen due to respiration in the bottom waters and in the sediments, and sets the stage for the development of seasonal hypoxia. A three-dimensional (3-D) coupled physical–biogeochemical model is used to investigate the dynamics of bottom hypoxia in the Black Sea NWS, first at seasonal and then at interannual scales (1981–2009), and to differentiate its driving factors (climatic versus eutrophication). Model skills are evaluated by a quantitative comparison of the model results to 14 123 in situ oxygen measurements available in the NOAA World Ocean and the Black Sea Commission databases, using different error metrics. This validation exercise shows that the model is able to represent the seasonal and interannual variability of the oxygen concentration and of the occurrence of hypoxia, as well as the spatial distribution of oxygen-depleted waters. During the period 1981–2009, each year exhibits seasonal bottom hypoxia at the end of summer. This phenomenon essentially covers the northern part of the NWS – which receives large inputs of nutrients from the Danube, Dniester and Dnieper rivers – and extends, during the years of severe hypoxia, towards the Romanian bay of Constanta. An index H which merges the aspects of the spatial and temporal extension of the hypoxic event is proposed to quantify, for each year, the intensity of hypoxia as an environmental stressor. In order to explain the interannual variability of H and to disentangle its drivers, we analyze the long time series of model results by means of a stepwise multiple linear regression. This statistical model gives a general relationship that links the intensity of hypoxia to eutrophication and climate-related variables. A total of 82% of the interannual variability of H is explained by the combination of four predictors: the annual riverine nitrate load (N), the sea surface temperature in the month preceding stratification (Ts), the amount of semi-labile organic matter accumulated in the sediments (C) and the sea surface temperature during late summer (Tf). Partial regression indicates that the climatic impact on hypoxia is almost as important as that of eutrophication. Accumulation of organic matter in the sediments introduces an important inertia in the recovery process after eutrophication, with a typical timescale of 9.3 yr. Seasonal fluctuations and the heterogeneous spatial distribution complicate the monitoring of bottom hypoxia, leading to contradictory conclusions when the interpretation is done from different sets of data. In particular, it appears that the recovery reported in the literature after 1995 was overestimated due to the use of observations concentrated in areas and months not typically affected by hypoxia. This stresses the urgent need for a dedicated monitoring effort in the Black Sea NWS focused on the areas and months concerned by recurrent hypoxic events.

scholarly journals Hydrology and circulation in the North Aegean (eastern Mediterranean) throughout 1997 and 1998

2002 ◽  
Vol 3 (1) ◽  
pp. 5 ◽  
Author(s):  
V. ZERVAKIS ◽  
D. GEORGOPOULOS
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Sea Water ◽  
Saline Water ◽  
Eastern Mediterranean ◽  
Late Summer ◽  
Cyclonic Circulation ◽  
The Black Sea ◽  
The North ◽  
North Aegean

The combination of two research projects offered us the opportunity to perform a comprehensive study of the seasonal evolution of the hydrological structure and the circulation of the North Aegean Sea, at the northern extremes of the eastern Mediterranean. The combination of brackish water inflow from the Dardanelles and the sea-bottom relief dictate the significant differences between the North and South Aegean water columns. The relatively warm and highly saline South Aegean waters enter the North Aegean through the dominant cyclonic circulation of the basin. In the North Aegean, three layers of distinct water masses of very different properties are observed: The 20-50 m thick surface layer is occupied mainly by Black Sea Water, modified on its way through the Bosphorus, the Sea of Marmara and the Dardanelles. Below the surface layer there is warm and highly saline water originating in the South Aegean and the Levantine, extending down to 350-400 m depth. Below this layer, the deeper-than-400 m basins of the North Aegean contain locally formed, very dense water with different θ /S characteristics at each subbasin. The circulation is characterised by a series of permanent, semi-permanent and transient mesoscale features, overlaid on the general slow cyclonic circulation of the Aegean. The mesoscale activity, while not necessarily important in enhancing isopycnal mixing in the region, in combination with the very high stratification of the upper layers, however, increases the residence time of the water of the upper layers in the general area of the North Aegean. As a result, water having out-flowed from the Black Sea in the winter, forms a separate distinct layer in the region in spring (lying between “younger” BSW and the Levantine origin water), and is still traceable in the water column in late summer.

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