气象与环境学报2018，Vol.34Issue(1)：38-44,7.DOI:10.3969/j.issn.1673-503X.2018.01.005
南海夏季风爆发前后柳州地区前汛期南风型暖区暴雨特征
Characteristics of warm-sector rainstorm with southerly flow during early-flood season in Liuzhou area before or after summer monsoon in the South China Sea
摘要
Abstract
The characteristics and circulation patterns of warm-sector rainstorms with the southerly flow in Liuzhou area occurring before or after the summer monsoon over the South China Sea from 2010 to 2015 were analyzed,u-sing observational data at conventional meteorological stations and regional automatic weather stations,as well as reanalysis data of National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) with the resolution of 1° ×1°.The results indicated that 72.7% of the warm-sector rainstorms with southerly flow occur after the break of summer monsoon over the South China Sea.The warm-sector rain-storms occurring before or after the summer monsoon over the South China Sea are characterized by a transport of positive vorticity at 500 hPa and a convergence zone near or below 925 hPa.The jets at super-low altitudes and the strong convergence of southerly flow within the boundary layer are the important triggering mechanism of the warm-sector rainstorms.The topography in the northern part of Liuzhou also favors the occurrence of a warm-sec-tor rainstorm,leading to a higher occurrence frequency of warm-sector rainstorm in this region.Before the occur-rence of summer monsoon in the South China Sea,the wet layer above the rainstorm area is very shallow,the inva-sion of dry and cold air at the middle levels favors the instability of atmospheric at upper levels of the rainstorm ar-ea,and the subtropics westerly jet is the major mechanism of divergence at upper levels.While after the occurrence of the summer monsoon in the South China Sea,the high pressure at South Asia is the mechanism of divergence at upper levels and the divergence is stronger at upper levels than lower levels.The strong "suction" action sustains the ascending motion at the upper levels of the rainstorm area.The deep wet layer in the rainstorm area is benefi-cial to enhance the precipitation efficiency and the formation of quasi-stationary mesoscale convective systems.关键词
南海夏季风/前汛期/暖区暴雨/"抽吸"作用/地形Key words
summer monsoon over the South China Sea/Early-flood season/Warm-sector rainstorm/Suction ac-tion/Topography分类
天文与地球科学引用本文复制引用
刘蕾,张凌云,陈茂钦,苏小玲,袁马强..南海夏季风爆发前后柳州地区前汛期南风型暖区暴雨特征[J].气象与环境学报,2018,34(1):38-44,7.基金项目
广西壮族自治区气象局气象科研计划(桂气科2016M15)资助. （桂气科2016M15）
