Characteristics of Variation of Sea Surface Temperature in the East Sea with the Passage of Typhoons

Abstract

In this study, the wind direction and the wind speed of the nearest temperature observations point of the National Weather Service was analyzed in order to investigate the rapid rise and drop of water temperature in the East Coast appeared after passing of the 2015 typhoon No. 9 and 11. Then the figures were simulated and analyzed using the WRF(weather research and forecast) model to investigate in more detailed path of the typhoon as well as the changes in the wind field.The results were as follows. A sudden drop of water temperature was confirmed due to upwelling on the East coast when ninth typhoon Chanhom is transformed from tropical cyclones into extra tropical cyclone, then kept moving eastwards from Pyongyang forming a strong southerly wind after 13th and this phenomenon lasted for two days. The high SST(sea surface temperature) is confirmed due to a strong northerly wind by 11th typhoon Nangka. This strong wind directly affected the east coast for three days causing the Ekman effect which transported high offshore surface waters to the coast. The downwelling occurred causing an accumulation of high temperature surface water. As a results, the SST of 15m and 25m rose to that of 5m.

Distributional Changes in Fishery Resource Diversity Caused by Typhoon Pathways in the East/Japan Sea

“…Typhoon path changes continue the southward or northward winds, causing upwelling or downwelling in coastal areas. If the coastal region facing the land is located on the right side of the typhoon radius during a typhoon, the northward wind continues to generate upwelling, while if it is located on the left side, the coast is affected by the southward wind [27][28][29]. Upwelling has a beneficial effect on organisms by providing nutrients to the surface layer, whereas downwelling causes oligotrophic seawater to migrate downward to the bottom layer and results in reduced biological productivity [27]; therefore, changes in the marine environment caused by the typhoon path can be transmitted to fishery resources.…”

“…Senju and Watanabe (1999) observed environmental changes in the EJS while typhoons passed along the northern coast of Japan [41], and Hong and Yoon (2003) proved that the post-typhoon SSC of the EJS was caused by coastal upwelling [12]. Additionally, Ekman transport, upwelling, and vertical mixing due to the passage of the typhoon change the temperature of middle, bottom, and surface waters [27,28,42,43], which affects the development and extinction of cold water along the coast of the EJS [29].…”