夏季东亚地区水汽输送的气候特征

Climatological Characteristics of Water Vapor Transfer over East Asia in Summer

摘要:

使用1980—1997年垂直积分的水汽输送通量资料,分析了夏季大尺度水汽输送演变的气候特征及偏南风水汽输送在中国区域内的推进特征。结果表明:夏季各支大尺度水汽输送汇合成一条行星尺度水汽输送大值带,它从南半球出发,经过亚洲季风区,进入北太平洋;东亚夏季偏南风水汽输送所能到达的北界为东北北部50°N附近;西太平洋副高南侧的东南风水汽输送所能到达的西界为甘肃东南部100°E附近。垂直积分的水汽输送通量强辐合区大多位于行星尺度水汽输送大值带中,与降水大值区之间有很好的对应关系。

关键词:夏季;垂直积分水汽输送;推进;水汽输送通量散度

Abstract:

Climatological characteristics are investigated for large-scale water vapor transfer over East Asia in summer based on the vertically integrated water vapor flux from 1980 to 1997.It is found that a planetary-scale water vapor transport band of high value is formed through the converging of large-scale water vapor transfer bands from different sources;and it starts from the southern Hemisphere,crosses the Asian monsoon area,and then flows to the north Pacific.The north border of moisture transferred by the East Asian southerlies is the north of northeast China near 50°N,and the west border of moisture transferred by the southeast wind from the south side of the West Pacific subtropical high the southeast of Gansu near 100°E.The strong convergence areas,which coincide with the heavy rain belts,mostly lie in the planetary-scale water vapor transport band of high value.

Key words:summer;the vertically integrated water vapor flux;progression;water vapor flux divergence