Influence of Latent Heat on the Process of a Heavy Rainfall Event in the Yangtze River-Huaihe River Basin in China
Based on the ground intensive observation and ERA5 reanalysis data,the latent heat and vertical movement diagnosis techniques were used to analyze the regional heavy precipitation process with long duration,strong hourly rainfall and large cumulative rainfall in the Yangtze-Huaihe region,and to study its maintenance mechanism.The results show that the heavy precipitation can be divided into two stages according to the influence system.The first stage is affected by the first low vortex and warm shear line,and the second stage is affected by the second low vortex and cold shear line.The heavy precipitation occurs in the low-level jet south of the low vortex and the shear line,which is a warm area heavy precipitation.There are similarities and differences in the maintenance mechanism of the two stages.The similarities are as follows:the positive feedback of latent heat in the rising movement of the synoptic scale system strengthens the rising movement and low-level jet;under the action of"jet self-excitation mechanism",the boundary layer rising movement develops,providing dynamic conditions for convection development.The differences are as follows:the boundary layer rising movement and the synoptic scale rising movement have a certain distance in the first stage,and the two positions are almost the same in the second stage,forming a deep rising movement area from the boundary layer to the middle and upper troposphere,maintaining the development of deep convection.
intense precipitationlatent heatself-excitation mechanism of jetmaintenance mechanism
国家科技期刊平台
NSTL
万方数据
