Influence of the atmospheric transport of suspended particles PM10 on the optical characteristics of the Black Sea surface layer

2021 ◽  
pp. 103513
Author(s):  
Dmitrii A. Kremenchutskii ◽  
Gennady F. Batrakov ◽  
Illarion I. Dovhyi ◽  
Yury A. Sapozhnikov

2019 ◽  
Vol 127 (10) ◽  
pp. 616
Author(s):  
В.Н. Носов ◽  
С.Б. Каледин ◽  
С.Г. Иванов ◽  
В.И. Тимонин

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.


2018 ◽  
Vol 17 ◽  
pp. 60-73 ◽  
Author(s):  
Liudmila V. Stelmakh ◽  
Tatiana I. Gorbunova

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.


2019 ◽  
Vol 487 (4) ◽  
pp. 443-447
Author(s):  
A. A. Sizov ◽  
T. M. Bayankina

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.


Author(s):  
B. N. Panov ◽  
E. O. Spiridonova ◽  
◽  

Russian fishermen harvest European anchovy primarily off the Black Sea coast of the Krasnodar Territory during its wintering and wintering migrations. At wintering grounds, temperature conditions become a secondary factor in determining the behaviour of commercial concentration of European anchovy, with wind and currents being the primary factors. Therefore, the aim of this work is to determine the potential use of daily data on water circulation and local atmospheric transport in short-term (1–7 days) forecasting of European anchovy fishing in the Black Sea. The research used the European anchovy fishery monitoring materials for January – March 2019, as well as daily maps of the Black and Azov Seas level anomalies (from satellite altimetry data) and surface atmospheric pressure and temperature in Europe (analysis) for the mentioned period. The dynamics of the catch rate and its relation to altimetry and atmospheric transport indicators in the north-eastern part of the Black Sea were investigated using graphical and correlation methods. This analysis showed that the main factor contributing to increased catches is intensification of northwest currents in the coastal 60-km zone. The effect of atmospheric transport on fishing efficiency depends on the mesoscale eddy structure of the nearshore current field. In the presence of an intense northwest current in the fishing area, southwest atmospheric transports have a positive effect on fishing, while in the presence of an anticyclonic meander of currents, northeast atmospheric transports become effective. The presence of maximum significant relationships when the determinants of fishing performance are shifted by 1–7 days allows making short-term predictions of fishing efficiency.


Ocean Science ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 491-501 ◽  
Author(s):  
G. I. Shapiro ◽  
D. L. Aleynik ◽  
L. D. Mee

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.


2013 ◽  
Vol 10 (6) ◽  
pp. 3943-3962 ◽  
Author(s):  
A. Capet ◽  
J.-M. Beckers ◽  
M. Grégoire

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.


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