Measurement of Attenuation at C Band in a Convective Storm by a Dual-Radar Method

Abstract

Abstract Retrievals of specific attenuation at 5.5-cm wavelength from dual-radar observations of a summer convective storm in Florida are presented. The retrieved specific attenuation is positive except in regions near the radars where the observed reflectivity factors suffered from contamination by ground clutter. The specific attenuations ranged between 0.0 and 2.0 dB km−1; they are small at higher levels of the storm, and high reflectivity cores are generally associated with higher specific attenuations. A plot of the retrieved specific attenuation against reflectivity factor at 10-cm wavelength shows that a majority of the retrieved values agree with those calculated from empirical relationships between reflectivity factor and specific attenuation. A small fraction of the points having high reflectivity factors have smaller than empirically predicted attenuations; these are attributed to dry ice particles. A larger fraction of the points having low reflectivity factors, less than about 30 dBZ, have hi...