Microphysical Insights From Dual Polarization Spectral Observations in Updraft and Mixed-Phase Precipitation

Abstract

This study presents dual polarization spectral analysis over updraft environments in thunderstorms. The composition and interaction of particle in updrafts environments are analyzed using the expansion that the spectral polarimetric provides in radar variables. Updrafts are identified using dual Doppler analysis and polarimetric signatures such as $Z_{\text{dr}}$ columns. Spectral techniques are presented to estimate the spectrum in updraft and mixed-phase environments. A separation in the spectrum of melting ice and rain was observed in the analyzed updrafts. This separation in the spectrum allows us to study the polarimetric characteristics and interaction of melting ice and rain. Furthermore, scattering simulations were carried out to validate the spectral signatures attributed to melting ice. It was found that small ice particles mixed with rain can produced similar polarimetric characteristics as the one observed in the spectral analysis. Conceptual models based on the spectral observations are presented to illustrate the interaction of ice particles with a recirculation and a vigorous updraft.

Keywords

• C-band
• coherent samples
• dual polarization
• precipitation
• remote sensing of electrification
• lightning