Analysis of circulation near the coast of Western Crimea and the region of Sevastopol with assimilation of temperature and salinity observations

Evstigneeva, N. A.; Демышев, С. Г.

doi:10.1088/1755-1315/386/1/012047

Cited by 3 publications

(3 citation statements)

References 8 publications

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“…According to the results obtained in the calculation in this study and in [25], the following circulation features were revealed: an anticyclonic eddy with a radius of about 15 km in the upper water layer in the Kalamita Bay, an anticyclonic eddy with a radius of about 15 km in the entire water layer between 32.2° E and 32.4° E related to the Rim Current meandering. On September 22 and 23, in the upper 36-meter layer the current, directed to the north and northwest, increased near Sevastopol and along the western coast of Crimea.…”

Section: The Potential Energy Variation Due Tosupporting

confidence: 55%

Generation of Vertical Fine Structure by the Internal Waves with the Regard for Turbulent Viscosity and Diffusion

Демышев¹,

Evstigneeva²,

Алексеев³

et al. 2021

PhO

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Purpose. The study is aimed at evaluating effectiveness of the procedure of the observational data assimilation using the Kalman filter algorithm as compared to sequential analysis of the hydrophysical fields based on the optimal interpolation method, and at analyzing the mesoscale features of coastal circulation near the western Crimea coast and in the Sevastopol region. Methods and Results. Based on the hydrodynamic model adapted to the Black Sea coastal zone conditions including the open boundary and on the temperature and salinity data from the hydrological survey in 2007, the dynamic and energy characteristics of the Black Sea coastal circulation were calculated with high spatial resolution (horizontal grid is ~ 1.6 × 1.6 km and 30 vertical horizons). The hydrophysical fields were reconstructed using two algorithms of data assimilation: the sequential optimal interpolation and the modified Kalman filter. The kinetic energy changed mainly due to the wind action, vertical friction and the work of pressure forces; the potential energy – due to the potential energy advection and the horizontal turbulent diffusion. The following circulation features were reconstructed: the anticyclonic eddy with the radius about 15 km in the Kalamita Bay in the water upper layer, the anticyclonic eddy with the radius about 15 km between 32.2 and 32.6° E in the whole water layer, the intense current near Sevastopol and along the Crimea western coast directed to the north and northwest, and the submesoscale eddies of different signs of rotation in the upper layer. Conclusions. It is shown that having been taken into account, heterogeneity and non-isotropy of the error estimates of the temperature and salinity fields relative to the correlation function lead to qualitative and quantitative differences in the hydrodynamic fields (amplification of currents, change of the currents’ direction and eddy formations were better pronounced). At the same time, the mean square errors of the thermohaline fields’ estimates decreased. Formation of the anticyclonic eddy with the radius about 15 km in the Kalamita Bay could be related to the current shear instability. Submesoscale eddies with the diameters less than 5 km were formed when the current flowed around the coastline and the bottom topography inhomogeneities.

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Section: The Potential Energy Variation Due Tosupporting

confidence: 55%

Generation of Vertical Fine Structure by the Internal Waves with the Regard for Turbulent Viscosity and Diffusion

Демышев¹,

Evstigneeva²,

Алексеев³

et al. 2021

PhO

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“…1). Control animals were maintained at salinity 18 ‰ (salinity of the Black Sea at the site of capture), and for experimental groups, mussels were exposed to low salinity (6 ‰, 10 ‰, 14 ‰) and high salinity (24 ‰, 30 ‰ and 40 ‰) (Evstigneeva & Demyshev, 2019). Water temperature, oxygen concentration and pH were equal for control and experimental groups and corresponded to those for acclimation period.…”

Section: Experimental Designmentioning

confidence: 99%

Short-time salinity fluctuations are strong activators of oxidative stress in Mediterranean mussel (Mytilus galloprovincialis)

Gostyukhina,

Kladchenko,

Chelebieva

et al. 2023

Ecol. Monten.

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Salinity stress is an emerging key factor affecting aquatic animals in coastal waters. In bivalves, physiological responses to anisosmotic conditions are frequently associated with excessive reactive oxygen species (ROS) formation, lipid peroxidation processes and alterations of the antioxidant enzyme activity in tissues. In this study, we investigated whether short-time exposure to high (20-40 ‰) or low (6-14 ‰) salinity induces oxidative stress in hemocytes and gills of Mediterranean mussel (Mytilus galloprovincialis). Our findings showed that both hypoosmotic and hyperosmotic stress enhanced formation of ROS in hemocytes, which was accompanied by an increase in DNA damage. Experimental acclimation to low salinity (6‰, 10 ‰) led to a decrease of the activity of superoxide dismutase but did not affect catalase activity in gills. Exposure to high salinity (24 ‰) inhibited activities of both antioxidant enzymes, whereas at 30 ‰ activity of both enzymes recovered up to controls. We found that exposure to high salinity was associated with lower risks of oxidative stress in mussels, and changes in redox balance are observed in hemocytes and gills even if the range of salinity changes is in range of species adaptive potential. Taken together, this study suggests that short-time salinity fluctuations promote oxidative stress in bivalves.

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“…По результатам, полученным в расчете в данном исследовании и в работе [25], были выявлены следующие особенности циркуляции: антициклонический вихрь с радиусом около 15 км в верхнем слое воды в Каламитском заливе, антициклонический вихрь с радиусом около 15 км во всем слое воды между 32,2° и 32,4° в. д., связанный с меандрированием Основного Черноморского течения. В верхнем 36-метровом слое 22 и 23 сентября усилилось течение вблизи Севастополя и вдоль западного берега Крыма, направленное на север и северо-запад.…”

Section: анализ энергетикиunclassified

Analysis of the Dynamic and Energy Characteristics of Water Circulation near the Western Crimea Coast and in the Sevastopol Region Based on the Observational Data Assimilation in the Numerical Model of the Black Sea Dynamics

Демышев¹,

Evstigneeva²,

Alekseev³

et al. 2021

MGZh

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Purpose. The study is aimed at evaluating effectiveness of the procedure of the observational data assimilation using the Kalman filter algorithm as compared to sequential analysis of the hydrophysical fields based on the optimal interpolation method, and at analyzing the mesoscale features of coastal circulation near the western Crimea coast and in the Sevastopol region. Methods and Results. Based on the hydrodynamic model adapted to the Black Sea coastal zone conditions including the open boundary and on the temperature and salinity data from the hydrological survey in 2007, the dynamic and energy characteristics of the Black Sea coastal circulation were calculated with high spatial resolution (horizontal grid is ~1.6×1.6 km and 30 vertical horizons). The hydrophysical fields were reconstructed using two algorithms of data assimilation: the sequential optimal interpolation and the modified Kalman filter. The kinetic energy changed mainly due to the wind action, vertical friction and the work of pressure forces; the potential energy – due to the potential energy advection and the horizontal turbulent diffusion. The following circulation features were reconstructed: the anticyclonic eddy with the radius about 15 km in the Kalamitsky Bay in the water upper layer, the anticyclonic eddy with the radius about 15 km between 32.2 and 32.6° E in the whole water layer, the intense current near Sevastopol and along the Crimea western coast directed to the north and northwest, and the submesoscale eddies of different signs of rotation in the upper layer. Conclusions. It is shown that having been taken into account, heterogeneity and non-isotropy of the error estimates of the temperature and salinity fields relative to the correlation function lead to qualitative and quantitative differences in the hydrodynamic fields (amplification of currents, change of the currents’ direction and eddy formations were better pronounced). At the same time, the mean square errors of the thermohaline fields’ estimates decreased. Formation of the anticyclonic eddy with the radius about 15 km in the Kalamitsky Bay could be related to the current shear instability. Submesoscale eddies with the diameters less than 5 km were formed when the current flowed around the coastline and the bottom topography inhomogeneities

show abstract

Analysis of circulation near the coast of Western Crimea and the region of Sevastopol with assimilation of temperature and salinity observations

Cited by 3 publications

References 8 publications

Generation of Vertical Fine Structure by the Internal Waves with the Regard for Turbulent Viscosity and Diffusion

Generation of Vertical Fine Structure by the Internal Waves with the Regard for Turbulent Viscosity and Diffusion

Short-time salinity fluctuations are strong activators of oxidative stress in Mediterranean mussel (Mytilus galloprovincialis)

Analysis of the Dynamic and Energy Characteristics of Water Circulation near the Western Crimea Coast and in the Sevastopol Region Based on the Observational Data Assimilation in the Numerical Model of the Black Sea Dynamics

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