东亚地区秋季水汽输送特征及水汽源地分析

CLIMATOLOGICAL CHRACTERISTICS OF WATER VAPOR TRANSPORT OVER EAST ASIAN AND WATER VAPOR SOURCE IN AUTUMN

用1980～1997年垂直积分的水汽输送通量资料,分析了秋季东亚地区大尺度水汽输送演变的气候特征以及主要水汽源地,结果表明:秋季各个月东亚大陆的主要水汽来源地并不相同,9月主要来源于孟加拉湾、南海和西太平洋地区;10～11月主要来源于南海、西太平洋地区。从夏季型到冬季型水汽输送的转换特征表现为:来自南半球的越赤道输送的显著减弱、消失直至转向,东亚南支偏西风水汽输送的逐渐建立,赤道太平洋地区的偏东风水汽输送的加强西进。秋季亚洲季风区范围最大的强水汽源地位于南海、西太平洋地区(115～120°E,15～25°N)。

Based on the vertically integrated water vapor flux from 1980 to 1997, climatological characteristics are investigated for large-scale water vapor transport over East Asia. It is found that in September, the moisture of East Asian is mainly from the Bay of Bengal, the South China Sea and the west Pacific Ocean; in October and November, the moisture comes from the South China Sea and the west Pacific Ocean. The features of change of transport pattern from summer to winter are as follows： The cross equatorial moisture transports decrease, disappear and turn ; the south westerly transports gradually establish; the easterlies water transport form equatorial Pacific gradually strengthen and march westward. In Autumn, the strongest water vapor source lies in the South China Sea and the west Pacific Ocean, in the region of 115-120 °E, 15-25°N.