Potential for attenuation-based estimations of rainfall rate from CloudSat

Abstract

Attenuation of radar signals in rain increases with frequency while the variability of non-attenuated reflectivity of rainfall diminishes as resonance scattering effects become more pronounced at higher radar frequencies. At mm-wavelength frequencies, attenuation often becomes the dominant factor responsible for apparent reflectivity changes in vertical. This study presents an attenuation-based method to retrieve vertical profiles of rain rate from nadir-pointing W-band (94 GHz) radars. The quantitative assessments of retrieval errors are discussed, and an illustration of the retrievals using measurements from the spaceborne 94 GHz CloudSat radar is shown. As a consistency check, the spaceborne W-band radar retrievals are compared with concurrent estimates from a ground-based weather surveillance radar. Copyright 2007 by the American Geophysical Union.