Effects of Vertical Wind Shear on the Pre-Summer Heavy Rainfall Budget:A Cloud-Resolving Modeling Study
SHEN Xin-Yong,QING Tao,HUANG Wen-Yan,LI Xiao-Fan
Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, China;Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, China;Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, China;National Oceanic and Atmospheric Administration/National Environmental Satellite, Data, and Information Service/Center for Satellite Applications and Research, Camp Springs, Maryland, USA
This study investigates the effects of vertical wind shear on the torrential rainfall response to the large-scale forcing using a rainfall separation analysis of a pair of two-dimensional cloud-resolving model sensitivity experiments for a pre-summer heavy rainfall event over southern China from 3–8 June 2008 coupled with National Centers for Environmental Prediction (NCEP)/Global Data Assimilation System (GDAS) data. The rainfall partitioning analysis based on the surface rainfall budget indicates that the exclusion of vertical wind shear decreases the contribution to total rainfall from the largest contributor, which is the rainfall associated with local atmospheric drying, water vapor divergence, and hydrometeor loss/convergence, through the reduction of the rainfall area and reduced rainfall during the rainfall event. The removal of vertical wind shear increases the contribution to total rainfall from the rainfall associated with local atmospheric drying, water vapor convergence, and hydrometeor loss/convergence through the expansion of the rainfall area and enhanced rainfall. The elimination of vertical wind shear enhances heavy rainfall and expands its area, whereas it reduces moderate rainfall and its area.
