Spectral densities of polarimetric variables obtained with the S-band radar in Oklahoma are presented. Polarimetric variables computed with standard techniques are biased if two or more types of scatterers with different polarimetric properties present in the radar resolution volume. The statistics of the intrinsic polarimetric variables computed from spectral densities can be unbiased and closer to the ensemble statistics of the echo type than the ones obtained with standard processing techniques. The distribution of polarimetric variables in velocity provides a unique way for observing multiple processes in each resolution volume and understanding the values of the resulting polarimetric averages. We examine polarimetric distributions in velocity as a function of (1) azimuth, (2) range, and (3) time from a clear air case on September 7, 2004.