The Research On Cloud Microphysical Characteristics Of Dual Polarization Radar Detecting Snowstorm/Rainstorm Vertical Structure

The dual linear polarization Doppler weather radar can simultaneously acquire radar-based data products and polarization parameters.Its RHI echo can sensitively and meticulously reflect the fine vertical structure of the precipitation cloud in advance,and make full use of various parameters to study the physical structure of the precipitation cloud.Studying the structure of wind temperature and humidity in the vertical direction of strong convective weather from the perspective of atmospheric energy,in-depth understanding of the atmospheric energy characteristics before it occurs,is helpful to discover and obtain its precursor information,and can deepen the understanding of the formation mechanism of different echoes.This article focuses on dual-polarization radar echoes and sounding data.Based on conventional weather analysis and satellite cloud images,the microphysical structure of precipitation clouds in the vertical direction of snowstorms and rainstorms in Nanjing is carefully analyzed and studied,revealing the evolution of the precipitation cloud phase and its precursors during the two precipitation processes.The main conclusions are as follows:?1?When dual polarization radar detects the evolution of heavy precipitation process,the polarization parameters are sensitive,precise and advanced to the change of cloud phase state and the physical structure of precipitation cloud.Contribution of all polarizations to study strong convective weather:Z_DR can identify the phase and shape of particles,?_HV can determine whether it is a single phase particle or a mixed phase particle,and K_DP has a better discrimination of rainstorm.All of them are sensitive to the identification of zero-level bright bands,and can be used in combination with actual forecast.?2?Based on the analysis of the dual-polarization radar RHI echo and sounding data,temperature-increasing stratus structure at 2km height during snowstorm,and the Z_DR RHI echo appears as a strong echo band at this height.The large number of small ice crystal particles produced by the ice crystal effect in the stratus.Another significant feature is the rime-attachment effect at a height of 5km to 6km.The Z_DR RHI echo shows a strong echo band at this height,which is called radar high band.The temperature of this height layer is low at-12?to-15?.It is an ice crystal layer produced by the process of agglomeration and agglomeration of cloud physics.When there are a lot of agglomerated particles,snow clusters form and fall down.?3?Analysis of atmospheric wind temperature and humidity data and dual polarization radar PPI echo showed that the dew point temperature of the air block at a height of 4.8km approximately during the rainstorm is extremely low,at about-20?to-40?.The lower layer of water vapor is brought into the low temperature area by the updraft and then cools and condenses to form a thin layer of cooling cold stratus.The cloud contains a large amount of ice crystals and super-cooled water droplets,which collide with each other and freeze,then form rime crystal particles,this is,rime-attachment particles and ice-snow crystal aggregates,it appears as strong Z_DR echo zones on PPI echoes.?4?The V-3? energy structure analysis method fully utilizes its characteristic layer information to clearly reveal the turning characteristics of water vapor unstable energy,vertical distribution state,and vertical wind shear in snowstorm and rainstorm.The appearance of"bee waist"and"big belly"structures,supper-low temperature,and irregular left folds are precursor information for weather forecasting and warning,which promotes the potential prediction of convection.