Seasonal differences in tropical cyclone—induced sea surface cooling in the western North Pacific

Abstract

AbstractTropical cyclone (TC)‐induced sea surface temperature (SST) cooling plays an important role in controlling the intensity of TCs in ocean basins and can modulate the local weather. This study examined the seasonal differences in TC‐induced SST cooling, especially between summer (June–August) and autumn (September–November), in the western North Pacific for the period 1992–2021. The analysis shows that the average maximum TC‐induced SST cooling along the TC track in autumn is 0.18°C less than in summer, although the mean TC intensity in autumn is 14 knots higher than in summer. This is because in autumn, the average mixed‐layer depth is 10–13 m deeper than in summer, and the TC track shifts equatorward, preventing the entrainment of cooler subsurface water to the surface, thereby causing less SST cooling in autumn at the same TC intensity. Given the negative feedback of TC‐induced SST cooling on TC intensity, these results are crucial to understand the seasonal differences in the intensity of TC in this basin.