江西一次持续性梅雨锋暴雨过程水汽特征及源地

利用江西省气象观测站降水资料、NCEP/NCAR提供的FNL 再分析资料以及GDAS 资料，在分析2020年7月7—10日的梅雨锋连续区域大暴雨过程的环流形势和大尺度水汽特征基础上，引入NOAA开发的HYSPLIT模式，分析了此次连续暴雨过程的水汽源地。结果表明：1） 此次连续性暴雨过程是在梅雨锋暴雨天气形势下，东北冷涡引导冷空气南下与副高北侧暖湿气流在长江中下游交汇形成的；2） 暴雨过程中不同时段水汽通道不相同，前两日以西南方向和偏南方向的水汽输送为主，后两日则以西南方向的水汽通道为主，且水汽通量大值区与强降水有较好的对应；3） 后向轨迹模拟显示暴雨过程水汽轨迹有5条：大部分为1 500 m高度以上源自印度洋的水汽（77.6%)，其次是1 500 m高度以下源自印尼群岛中部海域的水汽（13.2%），其他三条路径总和不足10%。4） 垂直方向上，有多条水汽输送通道相互叠加后向暴雨区输送，导致江西上空产生强的水汽辐合。

Characteristics and sources of water vapor during a continuous heavy rainstorm for a Meiyu front process in Jiangxi

Based on the precipitation data of Jiangxi province, FNL reanalysis data and GDAS data provided by NCEP/NCAR, according to the analysis of the circulation situation and large scale water vapor characteristics, the water vapor sources of a continuous heavy rain process in Jiangxi from July 7 to 10, 2020 were analyzed using HYSPLIT model developed by NOAA. The results showed that: 1) The continuous rainstorm process was formed under Meiyu front situation by the interaction between the cold air led by the northeast cold vortex with the warm and humid air flow on the north side of the subtropical high in the middle and lower reaches of the Yangtze River. 2) During the rainstorm, the water vapor channels were different in different periods. In the first two days, there was water vapor transport from the southwest and the south, while in the second two days, the water vapor channel was mainly from the southwest, and the high value area of water vapor flux presented a good correspondence with the heavy rainfall. 3) The backward trajectory simulation showed that there were five water vapor trajectories during the rainstorm process. Water vapor over 1 500 m mainly came from the Indian Ocean (77.6%), followed by the water vapor below 1 500 m coming from the central waters of Indonesia islands (13.2%), and the ratio of the other three trajectories was less than 10%. 4) Several water vapor transport channels superimposed in the vertical direction, resulting in large water vapor flux over Jiangxi.