Typhoon induced upper ocean cooling off northeastern Taiwan

Abstract

The ocean cooling off northeastern Taiwan induced by typhoons is complicated by the presence of the continental shelf of the East China Sea and the Kuroshio. The cooling is primarily due to the upwelling of the Kuroshio's subsurface water, which accompanies the Kuroshio's intrusion onto the shelf, rather than the entrainment mixing generated by the wind. The Kuroshio's intrusion in this region has a seasonal variation, being more substantial in winter than in summer. Previous studies found that the winter northeasterly monsoon creates an intrusion‐favored flow pattern, while the reversed summer monsoon opposes it. This study found that the strong northeast wind, accompanied by a typhoon along a certain path, could significantly alter the circulations on the shelf. An intrusion event will be triggered via a similar mechanism as induced by the winter monsoon, but at a faster pace. A numerical study and observation data are provided to illustrate this mechanism.