Study of a Convective Event During the Relampago Field Experiment Using Spectral Polarimetry

Abstract

Dual-polarization measurements from weather radars facilitate the study of size, shape and orientation of hydrometeors. Blending of Doppler information with polarimetric measurements enables spectral analysis and characterization of the dynamics of hydrometeors in a precipitating system. Study of spectral properties together with and polarimetric measurements is known as Spectral Polarimetry. This paper discusses the application of spectral polarimetry on dual-polarization radar observations from a convective event during the Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) field experiment [1]. Data from the C-Band CSU-CHIVO [2] radar have been used to investigate interesting microphysical phenomenon pertinent to convective storms. One such aspect is to study the presence of various particle size distribution resulting from a mixture of hydrometeors in a sheared environment and its implication on size sorting. Spectral variables are computed using raw radar measurements and subsequently combined with polarimetric methods. Presence of vertical wind shear is determined from dealiased radial Doppler velocity data. In particular, the slope of spectral differential reflectivity demonstrates the presence of different particle size distributions and their consequent size sorting in regions of heavy rainfall with mixture of hail.