Mapping Radar Reflectivity Values of Snowfall Between Frequency Bands

Motivated by the use of a K_u/K_a-band radar in the Global Precipitation Measurement core satellite due to launch in 2013, we have studied the use of techniques to simulate radar observations of snowfall at these bands from data at C/W-bands by using scattering simulations to derive the approximate relationships of radar observables at the C/W-bands and those at K_u/K_a-bands. In this paper, we form the cross-band relationships by simulating radar reflectivity and attenuation in snowfall. The relations can be used to simulate observations at given bands from measurements at other bands. When measurements are available at multiple frequencies, the consistency of the model and the measurements can be used as a measure of the validity of the underlying assumptions of snowflake shape and constitution, which have been an important topic in recent snowfall remote sensing research. We also present mapping functions that can be used to perform cross-band analysis of snowfall observations and examine the use of these for practical cases of combined ground- and space-based (CloudSat) radar measurements as well as airborne radar data from the 2003 Wakasa Bay experiment.