基于HYSPLIT模式分析云南四次冬季强降水水汽特征

Analysis of water vapor characteristics of four winter heavy precipitation in Yunnan based on HYSPLIT model

本文利用NCEP(National Centers for Environmental Prediction,NCEP)再分析资料、地面区域自动站资料和MICAPS(Meteorological Information Comprehensive Analysis and Processing System)资料对云南四次冬季强降水过程进行研究,再运用HYSPLIT模式(Hybrid Single-Particle Lagrangian Intergrated Trajectory)方法模拟影响云南冬季强降水的主要路径及不同源地的水汽贡献。结果表明:过程1受南支槽、切变线以及地面冷锋共同影响,是近年来云南冬季全省性暴雨的最强过程。过程2—4则仅受南支槽和地面冷锋或准静止锋影响。日平均整层水汽通量大小与暴雨站数具有明显正相关。降水时对流层低层至高层西、南边界均为水汽输入。过程1水汽收支最大,强降水范围最大。过程2、3水汽输入较大,但同时水汽输出也较大,收支中等,强降水范围次之。过程4水汽收支最小,强降水范围最小。云南暴雨区500 hPa的水汽中41%来自印度洋、55%来自大西洋、4%来自西太平洋。云南暴雨区700 hPa的水汽中26%来自西太平洋、59%来自印度洋、15%来自大西洋。地面以上100 m高度的水汽17%来自西太平洋、83%来自印度洋。对比四次过程水汽通量和降水实况,来自印度洋的水汽对于降水有重要作用。

Based on the reanalysis data from National Centers for Environmental Prediction(NCEP)and the ground area automatic station data and the data from Meteorological Information Comprehensive Analysis and Processing System(MICAPS),the characteristics of four winter heavy precipitation processes in Yunnan were studied.Then based on the model of Hybrid Single-Particle Lagrangian Intergrated Trajectory(HYSPLIT),the main paths affecting the winter heavy precipitation in Yunnan and the water vapor contributions from different sources were simulated.Results show that process 1,influenced by the south trough,the shear line and the surface cold front,is the strongest process of provincial heavy precipitation in winter of Yunnan in recent years.Processes 2 to 4 are only affected by the south trough and the surface cold front or the quasi-stationary front.The average daily water vapor flux of the whole layer is positively correlated with the number of rainstorm stations.When precipitation occurs,water vapor enters the west and south boundaries of the lower troposphere to the upper troposphere.Process 1 has the largest water vapor budget and range of heavy precipitation.In process 2 and 3,the input of water vapor is large,but the output of water vapor is large at the same time,so the budget and range of heavy precipitation is medium.Process 4 has the smallest water vapor budget and range of heavy precipitation.41%of the water vapor at 500 hPa above Yunnan rainstorm area comes from Indian Ocean,55%of the water vapor at 500 hPa above Yunnan rainstorm area comes from Atlantic Ocean,and 4%of the water vapor comes from western Pacific Ocean.26%of the water vapor at 700 hPa above Yunnan rainstorm area comes from the western Pacific,59%of the water vapor comes from the Indian Ocean,and 15%of the water vapor is from the Atlantic Ocean.17%of the water vapor at 100 meters above the surface comes from the western Pacific Ocean and 83%of the water vapor comes from the Indian Ocean.Comparing the water vapor flux and precipitation of the four processes,the water vapor from the Indian Ocean plays an important role in precipitation.