An Improved Method for Obtaining the Water Content Values of Ice Hydrometeors from Aircraft and Radar Data

Abstract

Uncertainty analyses and operational experience at the Air Force Geophysics Laboratory (AFGL) have shown that for single samples of ice hydrometeors, the factor ? = M/(??), where M (spectral liquid water content) and Z (spectral radar reflectivity factor) are computed from aircraft particle size information, is less subject to the uncertainties of converting the physical size of the particles into equivalent melted diameter than are M and Z themselves. Consequently, in correlating multiple-sample aircraft data with simultaneously acquired, independent radar measurements of ZR, there is an appreciable accuracy enhancement that can be attained in the derivation of M vs Z equations by regression means, if ? is used as the correlation parameter, versus ZR, rather than if spectral M is used as the correlation parameter.