Study on Generation Process of Kyucho

在日本中部面向黑潮的东南沿海，沿着的渔具网经常被一股沿海风暴流所摧毁。1994年1月9日，一条最大流速为0.65ms^的Kyucho在相模湾沿岸沿着奔腾，<-1>温度急剧上升，强流持续了约半天。NOAA-IR图像显示，黑潮暖流通过大岛西水道入侵，并沿相模湾沿岸沿着气旋性移动。1998年6月1日，在黑潮非大弯曲近岸路径向非大弯曲近海路径过渡的过程中，九尾带着高温水冲过大岛东航道，并沿着相模湾沿岸气旋性移动。海湾西北部10 m、35 m和60 m深度的海流记录显示，在Kyucho之前有几天的周期波动，并在6月1日突然放大。伊豆群岛附近海平面波动、串本海平面与浦上海平面差等资料表明，黑潮路径由非大曲流近岸路径向大曲流路径转变过程中出现了久町，由此推测黑潮的斜压不稳定性是导致暖水入侵的主要原因。因此，本文通过数值试验来阐明黑潮路径转捩引起的久潮的产生机制。

Kyucho, a coastal stormy current, often has destroyed fishing gear nets along the southeastern coast of the central Japan, facing to the Kuroshio. The purpose of this study is to clarify a generation process of a Kyucho in Sagami Bay as a model sea.On January 9, 1994, a Kyucho rushed along the Sagami Bay coast having the maximum velocity of 0.65ms^<-1> with a steep temperature rise, and the strong current continued for about half a day. NOAA-IR image showed that the warm water intrusion of the Kuroshio water through the Oshima west channel, and the water moving along the Sagami Bay coast cyclonically. The Kyucho occurred during the transition period from the non-large meander nearshore path of the Kuroshio to the non-large meander offshore path. On June 1,1998, the Kyucho rushed through the Oshima east channel with high temperature water and also moved along the Sagami Bay coast cyclonically. The current records at 10m, 35m and 60m depths at the northwest of the bay showed the several-days period fluctuation before the Kyucho and were suddenly amplified on June 1. The sea level fluctuations around Izu Islands and the sea level difference between Kushimoto and Uragami and the other data indicated that the Kyucho occurred during the Kuroshio path transition from non-large meander nearshore path to large meander path.This study proposes that the warm water intrusion is induced by the baroclinic instability of the Kuroshio. So, we are carrying out to clarify the generation mechanism of the Kyucho induced by the transition of the Kuroshio path by the numerical experiment.