A dual-wavelength radar method for ice-water characterization in mixed-phase clouds

Abstract

A dual-wavelength method to differentiate supercooled water from ice and to measure mass content in each phase in cold stratiform clouds is proposed and discussed. The differential attenuation Ad, whose direct measurement is available with dual-wavelength radar, is a linear function of the liquid water content Mw (the contribution from ice hydrometeors is negligible in comparison). Measuring both Ad and the radar reflectivity factor Ze leads to a system of two equations expressed as functions of Mw and Mi (ice water content); its solution provides the values of both Mw and Mi between any two ranges along the radar beam, and as a consequence the distribution pattern of those two parameters within the cloud. The wavelength couple of 3.2cm and 0.86cm has been selected as the most suitable one. -from Authors