Deintensification of typhoon Soulik by a rapid ocean destratification in the coastal waters of west Jeju Island, Korea

Abstract

The Yellow Sea is highly stratified during the summer with warm surface water, typically warmer than 25C and an extensive area of cold bottom water less than 15C. Strong tidal currents off the Jeju Island reach about 1.2 m/s with maximum tidal ranges of 3 m. During Typhoon Soulik, the glider observed rapid cooling. Surface temperatures dropped 11C, from 27.5C to 16.5C, bottom temperature increased by 3C, from 11C to 14C, and a dramatic deepening of the pycnocline from 30 to 70 meters depth. This rapid mixing coincided with a tidal transition after hours of sustained winds and waves with limited mixing and cooling. In this study, we present a preliminary analysis of typhoon Soulik and its interaction with this tidally dominated and highly stratified coastal ocean causing a typhoon deintensification by a rapid ocean destratification.