Latitudinal and Seasonal Variations in Tropical Cyclone-Induced Ocean Surface Cooling in the Tropical Western North Pacific

Abstract

The passage of tropical cyclones induces ocean surface cooling through vertical mixing, upwelling, and surface heat loss. The dependence of tropical cyclone-induced ocean surface cooling on the intensity and translation speed of tropical cyclones has been documented in previous studies. The present study investigates the latitudinal and seasonal variations in tropical cyclone-induced ocean surface cooling in the tropical western North Pacific based on data for the 2001–2020 period. Our analysis focuses on the open ocean (0°–25°N, 130°E–180°) to reduce the interference of coastal topography so that the obtained results better represent the influences of the intensity and translation speed of tropical cyclones. Our analysis confirms the dependence on the intensity and translation speed of tropical cyclone-induced cooling. The new findings are as follows. First, the time to reach the maximum cooling increases with the magnitude of the maximum cooling. Second, the magnitude of ocean surface cooling increases with latitude in the tropical region for tropical cyclones with different intensities and translation speeds. Third, the ocean surface cooling is larger in summer and autumn than in spring for tropical cyclones with different intensities and translation speeds. Fourth, the dependence of ocean surface cooling on the translation speed is more obvious at higher latitudes in the tropics and less apparent in spring. These new findings add to the existing knowledge of the impacts of tropical cyclone intensity and translation speed on ocean surface cooling.