紀伊半島沿岸域における台風通過に伴う海水温低下と海洋構造変化について

Abstract

Oceanic response to a series of typhoon passages is investigated with a triply-nested oceanic downscaling model forced by the assimilative GPV-MSM reanalysis dataset for the coastal marginal sea off Kii Peninsula, Japan. Temperature is decreased about 2 degrees for 2 weeks during three typhoons passing by. An EOF analysis decomposes the modeled SST properly into 1) a seasonal signal as a linear trend attributed to enhanced vertical mixing and mixed layer deepening due to the seasonal surface cooling in the 1st mode, 2) coastal upwelling at several locations through the Ekman transport due to the stormy surface wind field in the 2nd and 4th modes, and 3) SSH changes caused by the meso- and submeso-scale, cyclonic cold eddies near the topography and subsequent eastward transport by the Kuroshio in the 3rd mode.