Polarimetric radar observations of dust storms at C- and S-band

Abstract

Wind-lofted particles in dust storms exhibit repeatable polarimetric radar characteristics in one C-band and three S-band datasets, including reflectivity factor (ZH) <25 dBZ and copolar cross-correlation coefficient (ρhv) <0.65 (and often <0.50). Differential reflectivity (ZDR) varies substantially in dust storms, with values averaging <0 dB in an Arizona case and +1.5 to +4 dB in two southern Plains cases. C-band ZDR was generally +1 to +3 dB in a Kuwait dust storm, similar to the southern Plains cases. ZDR may exhibit small patches of values <–3 dB, especially when observing at an altitude <0.5 km above radar level. Whereas dusty and nondusty convective outflow boundaries may have similar ZH characteristics, non-dusty boundaries may be differentiated by their relatively higher ZDR and ρhv values.