Based on the hourly precipitation data of China's ground meteorological station in July 2019,ECMWF ERA5 reanalysis data and the DEM data from SRTM 250 m terrain digital elevation model of the US space shuttle"struggle",the causes and mechanisms characteristics of the persistent heavy precipitation in northern Guangxi caused by a low vortex(shear)are investigated.The results show that this process is caused by cold air moving southward and being obstructed by the terrain of northern Guangxi,and intersecting with warm and humid air,leading to frontogenesis and vigorous convection.Water vapor continuously transports and converges towards northern Guangxi,and the initial height of strong frontogenesis is relatively high and not deep.However,there is a certain amount of dry and cold air intrusion in the middle and lower layers,which enhances atmospheric instability and further stimulates strong frontogenesis and convection.With the supplement of cold air on the ground,the strong frontogenesis is lower in height and stronger in intensity,which represents the warm cloud precipitation with higher efficiency and indicates the occurrence of extreme daily precipitation.The change of frontogenesis structure can indicate the change of precipitation intensity to a certain extent,and can provide a meaningful focus for heavy precipitaiton forecast.
关键词
持续性强降水/地形/水汽辐合/锋生结构/暖云降水
Key words
persistent heavy precipitation/terrain/water vapor convergence/frontogenesis structure/warm cloud precipitation
维普
万方数据