Effects of Successive Typhoon Durian and Typhoon Utor on Chlorophyll-a Response in South China Sea

This paper investigated the effects of the successive Typhoons Durian and Utor on the chlorophyll-a concentration in the overlapping regions of the South China Sea in 2006. Satellite observations were employed to analyze the spatial–temporal variability of chlorophyll-a concentrations. The results show that the strong vertical mixing and upwelling after the passage of the first Typhoon Durian led to a rapid increase in chlorophyll-a concentration, while the effects of the subsequent Typhoon Utor showed regional variability: the chlorophyll-a concentration in the area to the right of the path of Typhoon Utor increased significantly, but it did not continue to increase in the area of the overlap with Durian and showed a decreasing trend. Studies have shown that the impacts of successive typhoons on marine ecology are not simply additive but can be modulated by changes in the marine environment caused by the previous typhoon. This study revealed the complexity of the impacts of successive typhoons on marine productivity and provides a new perspective for understanding how typhoons affect marine productivity.