深圳“5·11”特大暴雨过程的水汽输送特征分析

Analysis on Water Vapor Transport of the “5.11” Heavy Rainfall Process in Shenzhen

利用NCEP/NCAR逐日风场和湿度场再分析资料(1°×1°)和深圳气象站地面气象观测资料,通过水汽通量、水汽通量散度的计算,对深圳2014年"5.11"特大暴雨过程与水汽输送的配置关系进行了分析。研究表明:南海为此次暴雨过程的主要水汽源地,暴雨落区位于边界层偏南风低空急流的前方;此次特大暴雨过程中存在两支低空急流——西南风低空急流和边界层偏南风低空急流,它们作为水汽通道,为暴雨的发生发展提供了充沛水汽,其中,边界层偏南风低空急流对此次暴雨影响更大,边界层的摩擦辐合和水汽堆积,为本次强降水过程提供了十分有利的条件。

The NCEP/NCAR reanalyzed data and the hourly automatic observation data were used to study the characteristics of water vapor transportation during the＂5.11＂ heavy rain event in Shenzhen. The results show that the vital vapor source related to the heavy rainfall came from the South China Sea and heavy rainfall occured in front of the southly jet within boundary-lay. This event consisted of two low-level jets： one was the southwesterly low-level jet and the other was the southly jet within boundary-lay.The two jets were important channels of transporting water vapor for the occurrence and development of the rainstorm. And the southly jet within boundary-lay was more prominent, because frication convergence and water vapor accumulation within the planet boundary lay played an important role in the torrential rainfall event.