青藏高原东部及邻近地区水汽输送的气候特征

Climatological Characteristics of Water Vapor Transport over Eastern Part of Qinghai-Xizang Plateau and Its Surroundings

利用1980—1997年垂直积分的整层水汽输送通量资料,分析了青藏高原东部及其邻近地区水汽输送的气候特征。结果表明,该区的水汽输送具有明显的季节变化特征:冬、春季的水汽主要来源于中纬度的偏西风水汽输送,夏季(7月)主要来源于孟加拉湾和南海,秋季(10月)主要来源于西太平洋地区。季风携带的南来水汽在高原东侧地区的进退比较缓慢,8月初北扩到40°N附近,10月中旬南退出30°N,其强弱和进退异常能影响极端旱涝事件的发生。来自南海、西太平洋地区的水汽输送对高原东部及其邻近地区的影响值得关注。

Climatological characteristics for large scale water vapor transport over the eastern part of the Qinghai-Xizang Plateau and its surroundings are investigated based on the vertically integrated water vapor flux from 1980 to 1997. It is found that in winter and spring, the moisture of the region is mainly from the middle-latitude westerly water transport; in summer （July）, the moisture comes from the Bay of Bengle and the South China Sea, and in autumn the water vapor is from the west Pacific Ocean. The advance and retreat features of the moisture with southerlies over the region are slow. And the water vapor from south, whose abnormal action will affect the occurrence of floods and droughts, can advance nothwart to 40°N in August, and retreat southward to the south of 30°N in October. The enough attention should be paid to the influence of the water vapour transport from the South China Sea and the west Pacific Ocean on this region.