1997～1999年亚洲季风区夏季水汽输送的差异分析

The analysis of the water vapor transport difference in Asian Monsoon Regions in 1997—1999 summers

利用ECMWF的水汽和风场资料，对东亚、东南亚和印度季风区1997—1999年各年夏季（6～8月）300～1000hPa气层问的水汽输送及其差异进行了计算分析．结果表明：①水汽输送的经向通量，在印度尼西亚-中国南部-日本南部为向北（正）的通量，从1997年到1999年夏季经向通量是由弱变强再变弱，而在澳大利亚北部-印度尼西亚则是由强变弱再变强；②水汽输送的纬向通量，1997年夏季正输送的东西范围比1998年和1999年夏季要广，但南北范围较窄；③中国东南部、南海到日本东部海域的负水汽平流在1998年夏季最大；④风场散度引起的水汽通量散度，在阿拉伯海和孟加拉湾1998年夏季最小，在东亚和西太平洋地区这3年变化很大．

The characteristics and difference of the water vapor transport in the East Asian, South Asian and Indian monsoon region in 1997-1999 summer are analysed by using the monthly data of water vapor and wind fields at 1 000-300 hPa levels analysed by ECMWF. The analysed results show that：① the positive meridional flux of the water vapor transport in the Indonesia - south Japan - south China from weak to strong then to weak from 1997 summer to 1999 summer ,but in the Indonesia -north Australia from strong to weak then to strong; ② the positive zonal flux of the water vapor transport , in 1997 summer the area of the east - west is wider than 1998 summer＇ s and 1999 summer＇ s ,but the area of the south - north is narrower; ③the negative advection of water vapor in the area of south -east China, south sea and the vicinal sea of Japan in 1998 summer is biggest;④ the divergence of wind in Arabian Sea and Bengal Bay in 1998 summer is weakest , in East Asian and west pacific the change is very large in these three year＇s summer.