玛曲地区5—10月水汽通量及强降水水汽来源分析

Transportation paths of water vapor of heavy precipitation from May to October in Maqu

利用玛曲常规站1967-2008年24 h(20:00-20:00)降水资料、NCAR/NCEP月平均再分析资料,用NOAA HYSPLIT_4(混合单粒子拉格朗日积分)水汽轨迹模型,统计分析了玛曲地区5-10月的平均水汽输送通量和强降水水汽主要来源轨迹.结果表明玛曲地区5-10月水汽主要存在于400 hPa以下,各层中以700 hPa层中水汽最多,其次为500 hPa层.玛曲地区强降水水汽来源主要有两条路径,分别为西南水汽输送带与东南水汽输送带,同时玛曲地区5-10月逐月水汽追踪路径的变化间接反映了青藏高原逐月水汽变化的过程.

Based on the precipitation in Maqu and NCAR/NCEP reanalysis data from 1967 to 2008, the different characteristics of the average transportation paths of water vapor of heavy precipitation in Maqu region from May to October were studied in terms of the statistical analysis and the HYSPLIT_4 model. The results showed that water vapor in Maqu region from May to October mainly exists in 400 hPa and the maximum water vapor layer is 700 hPa, followed by the 500 hPa layer. There are two transportation paths of water vapor of heavy precipitation in Maqu, namely, the southwest water vapor conveyor belt and the southeast water vapor conveyor belt. Also, the monthly changes in the transportation paths of water vapor over Maqu are related to the monthly changes in the humidity of the Qinghai-Tibet plateau from May to October.