A study of meso-scale vortex-like convective clouds observed over the seas around Japan

日本周边海域观测到的中尺度涡旋对流云研究

• 批准号: 60460048
• 负责人: ASAI Tomio
• 金额: $ 4.35万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60460048/
• 关键词: meso-scale vortical cloud; convective cloud; convergence zone; horizontal shear; heavy snowfall; Japan Sea; 静止気象衛星; 中規模擾乱; 渦状雲; 気象衛星雲画像; 気象レーダー; meso-scale vortical cloud; convective cloud; convergence zone; horizontal shear; heavy snowfall; Japan Sea; 静止気象衛星; 中規模擾乱; 渦状雲; 気象衛星雲画像; 気象レーダー

Vortical convective cloud patterns in meso-scale ranging from[10km to [100km gave been frequently found over the seas around Japan, since observation by the geostationary meteorological satellite "Himawari" was available in 1987. The objectives of the present study is to elucidate seasonal and geographical distributions of meso-scale vortical convective clouds and mechanism of their development besed on an observational study and laboratory and numercal experiments.The results obtained so far are summarized as follows.(1) Statistical analyses of satellite cloud pictures show two preferred areas in the Sea of Japan in winter where meso-scale vortical clouds are most frequently observed : 1) east of Korea peninsula and 2) west of Hokkaido Island. These vortical clouds gaving cyclonic vorticity and life-time of several hours move to southeast in a speed of 10ms^<-1> and some of them vanish just after landing to coastal regions of Japan.(2)Band clouds accompanying horizontal convergence and cyclonic shear are observed and the vortical clouds are often formed in the bands : one is a convergence zone between northerly wind from Siberia and westerly wind from Korea peninsula and the other is a convergence zone between northwesterly from Siberia and northeasterly from Hokkaido. This suggests that meso-scale vortical disturbances may be formed favorably in the convergence zones.(3) A well-developed trough or a cold vortex in the upper troposphere and a northwesterly monsoon in the lower tropposphere provides a deep potentially unstable layer over the Sea of Japan. This is favorable for development of meso-scale vortical convective clouds in association with topographically induced convergence and shear zones.

Vortical convective cloud patterns in meso-scale ranging from[10km to [100km gave been frequently found over the seas around Japan, since observation by the geostationary meteorological satellite "Himawari" was available in 1987. The objectives of the present study is to elucidate seasonal and geographical distributions of meso-scale vortical convective clouds and mechanism of their development besed on an observational study and laboratory和数字实验。到目前为止获得的结果总结如下。（1）卫星云图片的统计分析显示，冬季最常观察到冬季最常见的冬季中日本海洋中的两个首选区域：1）韩国半岛以东和2）霍基多岛西部。这些巨大的乌云避免了几个小时的几个小时的狂热旋转时间，速度为10ms^<-1>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>（2）伴随着水平收敛和旋风的频率与涡流的形成的频率互动的频率在日本的沿海地区消失。韩国半岛和另一个是西伯利亚西北部和北海道的东北地区之间的融合区。这表明在收敛区中可以有利地形成中尺度的涡旋扰动。（3）在对流层上部有一个发达的槽或冷涡流，在下对流层中的西北季风中，在日本海洋中提供了深层潜在的不稳定层。这有利于与地形诱导的收敛和剪切区相关的中尺度涡流对流云的发展。