Identification And Characterization Of The Melting Layer Based On The Polarimetric Radar Scans

The melting layer?ML?is an important feature of stratiform precipitation,This layer is an important feature as it has an influence on quantity precipitation estimation.How to reduce this effect is a scientific issue of great concern to radar meteorological observation.Dual-polarization radar can provide dual polarization parameter information,which has advantages in cloud precipitation particle phase identification and particle size distribution.Analysis the polarimetric signatures of dual-polarization parameters can better identify the melting layer,and better analysis the vertical microphysics structural features of the melting layer.In this paper,firstly,the data qualities of the 714XDP-A X-band dual-polarization are analyzed and the attenuation correction are implemented because of the X-band radar signal serious attenuation in rain area.The attenuated reflectivity factor Z_H and differential reflectivity Z_DRR can be corrected by using observable K_DP.This is because the specific attenuation and the differential attenuation are nearly linear relationship with K_DP.In order to verify the revised effect,attenuation correction method is applied to the real cases.In this paper,a new way to identify the melting layer on RHI scans using texture of polarization parameters(SD?Z_H?,SD(Z_DR),SD(?_HV))is proposed and the revised results are compared to the mean vertical profile of reflectivity method?MVPR?in the same period.The result shows that using texture of polarization parameters can identify the melting layer and analyze the polarization characteristics.Then,the four polarization parameters Z_H,Z_DR,K_DP,?_HVV and the environmental temperature T as five input parameters,the fuzzy logic algorithm for hydrometeor particle identification is implemented to analyze to a real cases of stratiform rain situations.And the result can reflect the stratiform precipitation melting layer characteristics in the vertical structure.