Classification of the Yamase (cold northeasterly wind around Northeastern apan) based upon its air-mass vertical structures
Classification of the Yamase (cold northeasterly wind around Northeastern apan) based upon its air-mass vertical structures
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根据气团垂直结构对山濑（日本东北部周围的冷东北风）进行分类
DOI：
10.2151/jmsj1965.75.6_1053
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Hiromitsu Kanno
中科院分区：
文献类型：
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作者：
Hiromitsu Kanno
Yamase风-一种寒冷的东北风，在日本东北部夏季产生凉爽的天气-通过使用高空气象数据进行分类。对Yamase气团的垂直结构进行了聚类分析，将其划分为7个气团。研究了每个星团中Yamase气团的平均特征。地面低温区与Yamase气团高度成正比，但气团高度并不总是与东风高度相对应。在Yamase气团和东风都很高(超过800百帕)的情况下，地面东风吹过日本东北部，极低温区蔓延到太平洋一侧(第2和第6团)。在东风偏高(800百帕以上)而山泽气团较低(800百帕以下)的情况下，地面东风吹过日本东北部但地面温度不是很低，冷空气有效地被山脉(3号和5号群)阻挡。在东风和Yamase气团高度都较低的情况下，地面东风和低温区仅限于太平洋一侧(团1、4和7)。各群的Yamase风的出现具有季节依赖性，其中群6和群7的Yamase风只在6月刮，群2和群4的风主要出现在百度季节，群1和群3的风主要从百度后期吹到夏季，群5的风主要在夏季吹。地面气压型、锋面分布和平均500hPa位势高度场在每个星团中都有其独特的特征。年内Yamase风的出现表明，1980、1988、1993年的大凉年是由2、3、4类Yamase风引起的，而2号C！Uster 2的Yamase风具有浓厚的冷空气团，在造成夏季凉爽中起着特别重要的作用。
The Yamase wind -a cold northeasterly wind which produces cool weather in summer over northeastern Japan- was classified by using upper-air meteorological data. A cluster analysis was performed of the vertical structures of the Yamase air masses, which were divided into seven clusters. The mean features of the Yamase air mass in each cluster are investigated. The surface low temperature area is in proportion to the Yamase air mass height but the air mass height does not always correspond to the height of the easterly wind. In the case of the Yamase air mass and easterly wind being both high (over about 800 hPa), the surface easterly wind blows over northeastern Japan and an extremely low temperature area spreads over the Pacific side (Clusters 2 and 6). In the case of the easterly wind being high (over about 800 hPa) but the Yamase air mass being low (below about 800 hPa), the surface easterly wind blows over northeastern Japan but the surface temperature is not extremely low, and the cold air is effectively blocked by the mountain range (Clusters 3 and 5). In the case of the easterly wind and Yamase air mass heights being both low, the surface easterly wind and low temperature area are restricted to the Pacific side (Clusters 1, 4 and 7). The Yamase wind appearances in each cluster show a seasonal dependence; the Yamase wind included in Clusters 6 and 7 blows only in June, that in Clusters 2 and 4 appears mainly in the Baiu season, in Clusters 1 and 3 it blows from late Baiu to summer, and in Cluster 5 blows in the summer season. Also the surface pressure pattern, front distribution, and the mean 500 hPa geopotential height field have the unique characteristics in each cluster. The Yamase-wind appearances in each year indicate that the severe cool summer years (1980, 1988, 1993) are induced by the Yamase winds classified in Clusters 2, 3, and 4; however, the Yamase wind in C!uster 2 having a thick and cold air mass plays an especially important role in causing a cool summer.