SEA-SURFACE COOLING CAUSED BY TYPHOONS IN THE TOHOKU AREA IN AUGUST 1989

A remarkable sea surface cooling event was observed in the north weste rn Pacific off Japan coast, which is known as the Tohoku Area, by usin g well-calibrated satellite sea surface temperature images, when typho ons T8914 and T8915 passed over the Tohoku Area in August 1989. The se a surface cooling maximum reached up to 9 degrees C, which is much lar ger than that reported in the previous studies. The corresponding hydr ographic data show that the sea surface cooling state is closely relat ed with the ocean structure in the Tohoku Area; the larger sea surface cooling occurs in the Oyashio area. The numerical experiments taking account of the ocean structure show that the surface cooling maximum i s 3-4 times larger in case of the Oyashio profile than that of the Kur oshio profile and clarify the mechanism of the sea surface cooling.