Dual-frequency Spaceborne Doppler Radar: analysis of performances in estimating latent heat fluxes

摘要

Knowledge of the global distribution of the vertical velocity of precipitation is important for estimating latent heat fluxes, and therefore in the general study of energy transportation in the atmosphere. Such knowledge can only be acquired with the use of spaceborne Doppler precipitation radars. Recent studies have shown that the average vertical velocity can be measured to acceptable accuracy levels by appropriate selection of radar parameters. Furthermore, methods to correct for specific errors arising from Non-Uniform Beam Filling effects and pointing uncertainties have recently been developed. As detailed in the Global Precipitation Mission (GPM) preparatory studies, the use of a dual-frequency precipitation radar allows improved estimation of the main parameters of the hydrometeor size distribution (bulk quantity and one shape parameter). Such parameters, in turn, lead to improved estimates of latent heat fluxes. In this paper we address the performance of a dual- frequency Doppler Precipitation Radar (DDPR) in estimating the latent heat flux from the measured rainfall vertical velocity and DSD parameters.