Kyucho induced by intrusion of Kuroshio water in Sagami Bay, Japan

On January 9, 1994, a Kyucho (stormy current) rushed along the Sagami Bay c oast and destroyed the fishing set-net at the western side of the bay head. The current record at 10 m depth, at a mooring station near the destroyed set-net, showed that the maximum velocity was 0.65 ms(-1) with a steep temp erature rise, and the strong current continued for about half a day. The th ermal front is estimated to have moved cyclonically at the speed of 0.6-0.7 ms(-1) from the temperature records at four stations along the bay coast. The successive satellite images, NOAA-IR, also showed the warm water intrus ion of the Kuroshio water through the Oshima west channel and moving cyclon ically along the coast. The CTD casts in the bay indicated high temperature and high salinity water with the thickness of 70 m and width of 15 km. The behavior of the Kyucho is similar to that of the coastal density current i n a rotating fluid, theoretically derived by Kubokawa and Hanawa (1984b). T he temperature variations in the Kuroshio region suggest that the Kyucho oc curred during the transition period from the non-meander nearshore path of the Kuroshio to the non-large meander offshore path. (C) 1999 Elsevier Scie nce Ltd. All rights reserved.