Study on Dynamics of Kyucho

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Kyucho, coastal stormy current, often has destroyed the fishing set-net in Sagami Bay, located at the southeastern coast of the central Japan. We have tried to clarify dynamics of the coastal stormy current.On January 9, 1994, a Kyucho rushed along the Sagami Bay coast having the maximum velocity was 0.65msィイD1-1ィエD1 with a steep temperature rise, and the strong current continued for about half a day. NOAA-IR image showed the warm water intrusion of the Kuroshio water through the Oshima west channel and moving cyclonically along the coast. The behavior of the Kyucho is similar to that of the coastal density current in a rotating fluid. The Kyucho was suggested to occur during the transition period from the non-meander nearshore path of the Kuroshio to the non-large meander offshore path.Kyucho, on September 18, 1988, caused fishing set-net to drift 8km along the coast in the southward current. The temperature rise at 30m depth moves with speed of 0.6msィイD1-1ィエD1 cyclonically. which it almost agrees with the maximum current at the moored stations. The temperature variations at 60m depth are very similar to the sea-level variations on the Sagami Bay coast. The sea-level variations propagated at 2.1-2.5msィイD1-1ィエD1, trapped at the coast cyclonically. These phenomena are similar to the characteristics of coastally trapped waves, and appear to be generated by the warm water that is piled up the coast by Ekman transport of the strong southward wind stress associated with Typhoon 8818.