Mie Scattering Detection Using the CSU-CHILL Dual-Wavelength Dual-Polarization Radar

The CSU-CHILL weather radar is capable of simultaneous dual-wavelength, dual-polarization data collection at S-band and X-band as described in [1].

The availability of a simultaneous, collocated polarimetric data set at two different wavelengths allows studying the hydrometeors present in the radar resolution volume through the difference in their scattering properties at each wavelength.

Building on a cost-function minimization method introduced in [2], this paper will present the method used to obtain the Mie signal together with relevant observations. In some cases the Mie signal reveals information not discernible through the usual set of dual-polarization parameters: the figures below show the Mie signal indicating the presence of larger particles in the ice portion of the storm above the descending hail shaft (likely hail stone embryos), whereas the rest of dual-polarization parameters (LDR, Z_DR, ρ_HV) only show the hail core.

[1] Junyent, F., V.V. Chandrasekar, V.N. Bringi, S.A. Rutledge, P.C. Kennedy, D.D. Brunkow, J.J. George, and R.R. Bowie, 2015: Transformation of the CSU–CHILL Radar Facility to a Dual-Frequency, Dual-Polarization Doppler System. Bull. Amer. Meteor. Soc., 96, 975–996, doi: 10.1175/BAMS-D-13-00150.1.

[2] Junyent, F. and V.V. Chandrasekar, 2016: An Examination of Precipitation Using CSU–CHILL Dual-Wavelength, Dual-Polarization Radar Observations. J. Atmos. Oceanic Technol., 33, 313–329, doi: 10.1175/JTECH-D-14-00229.1.