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.

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 Interannual Variability of the Wind-Wave Regime Parameters in the Black Sea

2020 ◽  
Vol 27 (5) ◽  
Author(s):  
P. N. Lishaev ◽  
V. V. Knysh ◽  
G. K. Korotaev ◽  
◽  
◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Black Sea ◽  
Mixed Layer ◽  
Mixed Layer Depth ◽  
Sea Surface ◽  
Temperature Fields ◽  
The Black Sea ◽  
Layer Depth ◽  
Upper Mixed Layer

Purpose. The investigation is aimed at increasing accuracy of the temperature field reconstruction in the Black Sea upper layer. For this purpose, satellite observations of the sea surface temperature and the three-dimensional fields of temperature (in the 50–500 m layer) and salinity (in the 2.5–500 m layer) pseudo-measurements, previously calculated by the altimetry and the Argo floats data, were jointly assimilated in the Marine Hydrophysical Institute model. Methods and Results. Assimilation of the sea surface temperature satellite observations is the most effective instrument in case the discrepancies between the sea surface and the model temperatures are extrapolated over the upper mixed layer depth up to its lower boundary. Having been analyzed, the temperature profiles resulted from the forecast calculation for 2012 and from the Argo float measurements made it possible to obtain a simple criterion (bound to the model grid) for determining the upper mixed layer depth, namely the horizon on which the temperature gradient was less or equal to ≤ 0.017 °C/m. Within the upper mixed layer depth, the nudging procedure of satellite temperature measurements with the selected relaxation factor and the measurement errors taken into account was used in the heat transfer equation. The temperature and salinity pseudo-measurements were assimilated in the model by the previously proposed adaptive statistics method. To test the results of the sea surface temperature assimilation, the Black Sea hydrophysical fields were reanalyzed for 2012. The winter-spring period (January – April, December) is characterized by the high upper mixed layer depths, well reproducible by the Pacanowski – Philander parameterization, and also by the low values (as compared to the measured ones) of the basin-averaged monthly mean square deviations of the simulated temperature fields. The increased mean square deviations in July – September are explained by absence of the upper mixed layer in the temperature profiles measured by the Argo floats that is not reproduced by the Pacanowski – Philander parameterization. Conclusions. The algorithm for assimilating the sea surface temperature together with the profiles of the temperature and salinity pseudo-measurements reconstructed from the altimetry data was realized. Application of the upper mixed layer depths estimated by the temperature vertical profiles made it possible to correct effectively the model temperature by the satellite-derived sea surface temperature, especially for a winter-spring period. It permitted to reconstruct the temperature fields in the sea upper layer for 2012 with acceptable accuracy.

Effect of phytoplankton adaptation on the distribution of its biomass and chlorophyll a concentration in the surface layer of the Black Sea

2019 ◽  
Vol 48 (4) ◽  
pp. 404-414 ◽  
Author(s):  
Liudmila Stelmakh ◽  
Tatiana Gorbunova
Keyword(s):  
Surface Layer ◽  
Spatial Variability ◽  
Black Sea ◽  
Phytoplankton Biomass ◽  
Abiotic Factors ◽  
Nitrogen Concentration ◽  
The Black Sea ◽  
Total Phytoplankton ◽  
Upper Mixed Layer ◽  
Effect Of Light

Abstract Using the field data collected in the Black Sea in September 2005–May 2013, the authors studied the spatial variability of the ratio of organic carbon to chlorophyll a (C:Chl a) in the sea surface layer (0–1 m). The C:Chl a ratio is an important parameter that reflects the phytoplankton adaptation to abiotic factors. Its maximum variations occurred in September–October 2005 and October 2010 when the highest spatial variability of average light intensity and nitrogen concentration was observed in the upper mixed layer. As a result, the maps of phytoplankton biomass differed from chlorophyll maps. In August 2011, no effect of light or nitrogen on the spatial variability of the C:Chl a ratio was found. Changes in the contribution of dinoflagellates to the total phytoplankton biomass affected the C:Chl a ratio variability, which was two times lower compared to September–October 2005 and October 2010. Also, the spatial distribution of phytoplankton biomass differed from the distribution of chlorophyll a concentration only in some areas of the sea. In May 2013, environmental factors slightly varied across the study area and the spatial variability of the C:Chl a ratio was insignificant. Therefore, the map of phytoplankton biomass indicated similarities with the chlorophyll map.

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

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.

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.

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