UPWELLING INDEX AT THE SOUTHERN COAST OF CRIMEA IN THE BLACK SEA
Авторы:
1.
Marine Hydrophysical Institute of RAS
Россия
Россия
2.
Marine Hydrophysical Institute of RAS
Россия
Россия
3.
Marine Hydrophysical Institute of RAS
Россия
Россия
4.
V.I. Vernadsky Crimean Federal University
Россия
Россия
Тип:
Статья
Страницы:
с 312
по 325
Статус:
Опубликован
Получено:
18.11.2024
Одобрено:
29.11.2024
Опубликовано:
20.07.2025
Язык материала:
русский
Ключевые слова:
coastal upwelling, upwelling index, sea water temperature, wind speed, wind direction, Katsiveli, Southern Coast of Crimea, Black Sea
Финансирование:
the study was carried out within the framework of state assignments of FSBSI FRC MHI: FNNN-2024-0014 and FNNN-2024-0016
Аннотация (русский):
Purpose. The purpose of the study is to analyze wind conditions leading to the occurrence of coastal upwelling events off the Southern Coast of Crimea (Katsiveli) in the Black Sea based on the calculations of wind upwelling index. Methods and Results. The 6-hour ERA5 reanalysis data of surface wind speed components, long-term measurements of seawater and air temperature near the coast in Katsiveli (1992–2021), as well as satellite maps of sea surface temperature are used. The upwelling index is calculated as Ekman transport driven by alongshore winds. The index is considered to be positive when the transport is directed offshore. For the Katsiveli area, this condition corresponds to winds with a western component. Negative values of the index and onshore water transport correspond to eastern winds. Calculations of the upwelling index shown that the most favorable wind conditions for upwelling events are observed in winter (December and January) and summer (June and July), driven by the high frequency of western winds. The maximum value of the upwelling index is noted in June. The statistical relationship between the monthly mean upwelling index, water temperature, number of upwellings, and the frequency and speed of western winds is analyzed for this month. It is found that the upwelling index in June correlates with the number of low water temperature events (indicative of upwelling). The correlation coefficient between them is 0.88. During the years characterized by high frequency and speed of western winds, the number of upwellings increased, whereas it was minimal when eastern winds predominated. Analysis of the variability of wind index and seawater temperature based on the 6-hour data shows that high positive values of the index correspond to the onset of upwellings, while a negative index indicates their cessation. Conclusions. Good agreement between the wind index variability and the number of measurements at low water temperature in summer demonstrates the potential of the index for studying wind conditions resulting in the development of upwelling events, as well as for forecasting their occurrence.
Purpose. The purpose of the study is to analyze wind conditions leading to the occurrence of coastal upwelling events off the Southern Coast of Crimea (Katsiveli) in the Black Sea based on the calculations of wind upwelling index. Methods and Results. The 6-hour ERA5 reanalysis data of surface wind speed components, long-term measurements of seawater and air temperature near the coast in Katsiveli (1992–2021), as well as satellite maps of sea surface temperature are used. The upwelling index is calculated as Ekman transport driven by alongshore winds. The index is considered to be positive when the transport is directed offshore. For the Katsiveli area, this condition corresponds to winds with a western component. Negative values of the index and onshore water transport correspond to eastern winds. Calculations of the upwelling index shown that the most favorable wind conditions for upwelling events are observed in winter (December and January) and summer (June and July), driven by the high frequency of western winds. The maximum value of the upwelling index is noted in June. The statistical relationship between the monthly mean upwelling index, water temperature, number of upwellings, and the frequency and speed of western winds is analyzed for this month. It is found that the upwelling index in June correlates with the number of low water temperature events (indicative of upwelling). The correlation coefficient between them is 0.88. During the years characterized by high frequency and speed of western winds, the number of upwellings increased, whereas it was minimal when eastern winds predominated. Analysis of the variability of wind index and seawater temperature based on the 6-hour data shows that high positive values of the index correspond to the onset of upwellings, while a negative index indicates their cessation. Conclusions. Good agreement between the wind index variability and the number of measurements at low water temperature in summer demonstrates the potential of the index for studying wind conditions resulting in the development of upwelling events, as well as for forecasting their occurrence.
Ключевые слова:
coastal upwelling, upwelling index, sea water temperature, wind speed, wind direction, Katsiveli, Southern Coast of Crimea, Black Sea
coastal upwelling, upwelling index, sea water temperature, wind speed, wind direction, Katsiveli, Southern Coast of Crimea, Black Sea
