Three-Dimensional Attributes of Clear-Air Scatterers Observed With the Polarimetric Weather Radar

In this letter, we present a spectral technique for observation and analysis of scatterers´ polarimetric attributes. This technique allows one to visualize the scatterers´ spectral signatures as a function of azimuth, Doppler velocity, and polarimetric variable at the same time. Such visualization can be used to evaluate the participants of the detected motions, to understand what constitutes the polarimetric averages, and to provide resources for establishing intrinsic polarimetric values (functions) for different types of scatterers, which are necessary for the scatterers´ classification algorithms. We demonstrate this technique on a clear-air case observed with the S-band polarimetric research radar in Norman, OK, on September 7, 2004. We discuss the preference for spectral density of backscatter differential phase versus other polarimetric spectral densities for the observations of clear air. The proposed visualization technique is not limited to observations of echoes in clear air and invites study of intrinsic properties for other types of scatterers.