Study on Generation Process of Kyucho

九鸟生成过程研究

基本信息

批准号：
12640420
负责人：
MATSUYAMA Masaji
金额：
$ 2.3万
依托单位：
Tokyo University of Fisheries
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640420/
关键词：
Kyucho Density Current Kuroshio Warm water Instrusion Baroclinic Instability Sagami Bay Numerical Model Moored measurements 黒潮回転系での密度流相模湾・東京湾数値モデル実験

项目摘要

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.

急流是一种沿海风暴流，经常破坏日本中部东南沿海面向黑潮的渔具网。本研究的目的是阐明相模湾作为模型海的急鸟的生成过程。1994年1月9日，一艘急鸟以最大速度0.65ms^<-1>沿着相模湾海岸冲过，气温急剧上升，强流持续了半天左右。 NOAA-IR图像显示，黑潮暖水通过大岛西航道入侵，并沿着相模湾海岸呈气旋式移动。九町发生在黑潮非大曲流近岸路径向非大曲流近岸路径的过渡时期。 1998年6月1日，急流带着高温水冲过大岛东航道，并沿相模湾沿岸呈气旋状移动。海湾西北部10m、35m、60m深度的当前记录显示，九町之前有数日周期波动，并于6月1日突然放大。伊豆群岛周边海平面波动以及串本和浦上之间的海平面差异其他数据表明，九潮发生在黑潮路径从非大曲流近岸路径向大曲流路径过渡期间。本研究认为，暖水入侵是诱发的由于黑潮的斜压不稳定。因此，我们正在通过数值实验来阐明黑潮路径转变引起的急潮的产生机制。