【摘要】 利用NOAA HYSPLIT₄水汽轨迹模型及1948—2003年NCAR/NCEP再分析资料,分析了华北地区夏季的平均水汽输送通量和轨迹。结果表明,华北夏季水汽轨迹有明显的年代际变化特征。1950—1970年代,华北地区850 hPa上的水汽主要是从南方输送来的,从1970年代开始水汽输送方向变以偏西为主,1980年代至今则以西北为主。另外,华北地区在1960—1964年垂直积分的水汽输送通量存在最大值,1965年以后水汽输送通量值开始变小,1977年后水汽输送通量值较小且保持稳定。水汽输送通量和水汽输送轨迹的变化主要和东亚夏季风的逐渐减弱有关。华北地区1950—2000年代夏季（6⁸月）逐月水汽输送轨迹变化特征明显。更多还原

【Abstract】 By using the HYSPLIT₄ Model and NCAR/ NCEP reanalysis data form 1948 to 2003,the interdecadal variations of the water vapor transportation paths over North China in summer（JJA） have been calculated and discussed in this paper.The results showed that the characteristics of water vapor transportation change were obvious.The dominant direction of the water vapor transportation at 850 hPa over North China in summer（JJA） from 1950 to 1970 was from south.In 1970′s,the direction of the water vapor transportation became from west and it was from northwest in 1980′s.In addition,there was maximum for the vertical integral of vapor fluxes from 1960 to 1964,which began to decrease from 1965.The vapor flux was less and stable since 1977.The variations of the water vapor transportation paths is related with the weaken of summer monsoon over East Asia.The character of water vapor transportation path in North China region in summer months（JJA） is very different from 1950′s to 2000′s.更多还原