ФРОНТЫ В ЖЕЛТОМ И ВОСТОЧНО-КИТАЙСКОМ МОРЯХ: ТЕМАТИЧЕСКОЕ ИССЛЕДОВАНИЕ

Abstract

Monthly-mean high-resolution satellite sea surface temperature (SST) measurements (PATHFINDER dataset) for the period of 1982-2009 along with the selected satellite infrared and visible images have been used to update and extend the knowledge of the structure, mesoscale features, seasonal and interannual variability of the fronts in the Yellow and East China Seas. The patterns of the general circulation, frontogenesis processes and phenomenology of the fronts are outlined. Seasonal variability of the selected most prominent local fronts has been documented. The major result is that when the climatological averaging is applied, the fronts at the boundary of East China Sea (Taiwan front, Kuroshio frontal zone and Tsushima front) appear as unified dominating frontal structure. This structure is about 1200 km length, spreads along the continental shelf from Taiwan to Tsushima and separates productive sea waters from the oligotrophic oceanic waters. This frontal structure appears as a persistent coherent feature throughout the year. However, it reveals seasonal variability of the SST gradient intensity. Maximum intensity is observed during the cold season (January- April), when the SST contrasts between the warm waters of Kuroshio and cooling waters of East China Sea are the highest. To study the long-term variability of this frontal system, the maximum meridional gradient of SST in the area of Kuroshio frontal zone in February have been calculated. The results reveal an existence of the pronounced interannual variability of SST gradient with the periods consistent with the ENSO (4-5 years). Statistically significant positive correlation (R = 0.57, p<0.01) between the SST gradient and Multivariate ENSO Index (MEI) was found.