Абстракт
Seasonal and interannual variability of the intensity of the Benguela upwelling is studied on the basis of satellite measurements of surface salinity of the ocean. Benguela upwelling causes intense rise of deep waters with low salinity and high nutrient content. The desalinated waters raised by the upwelling spread under the influence of horizontal advection to the west, affecting the thermohaline structure of the western part of the South Atlantic Ocean. The analysis showed that the maximum salinity values in the northern Benguela upwelling, corresponding to the weakening of upwelling, are observed from April to June, the lowest in October–December with a secondary minimum in February-March. The seasonal course of salinity is different from the variability of temperature, because upwelling waters are subject to seasonal warming, which in turn masks an increase in upwelling in October–November in the field of surface temperature. Satellite measurements record a significant short-period variability of upwelling salinity, which is associated with the passage of Antarctic cyclones. When the eastern periphery of the cyclone interacts with the continent, a zone of intense southerly winds forms near the coast, which lead to downwelling and an increase in salinity by 0.5 PSU. The displacement of the tracks of such cyclones to the north in certain years is one of the important reasons for the observed interannual variability of salinity, in particular, a sharp increase in salinity and a decrease in the intensity of upwelling in 2018. © 2023 Space Research Institute of the Russian Academy of Sciences. All rights reserved.
Ключевые слова
БЕНГЕЛЬСКИЙ АПВЕЛЛИНГ, СЕЗОННАЯ И МЕЖГОДОВАЯ ИЗМЕНЧИВОСТЬ, ПОВЕРХНОСТНАЯ СОЛЁНОСТЬ, СПУТНИКОВЫЕ ИЗМЕРЕНИЯ, SMAP, Benguelа upwelling, satellite measurements, seasonal and interannual variability, SMAP, surface salinity