Disentangling Mie and attenuation effects in rain using a Ka-W dual-wavelength Doppler spectral ratio technique

A novel technique that enables to disentangle Mie and attenuation effects in coincident, beam-matched Ka- and W-band radar observations is presented here. The ratio of the measured radar Doppler spectra at the two frequencies is estimated, and the Doppler velocity regime that corresponds to Rayleigh scatterers is determined. The range variation of the Rayleigh regime "plateau" is directly linked to the differential attenuation between the two wavelengths and does represent the attenuation component of the dual-wavelength ratio. The retrieval technique is applied to a light stratiform rain event and provides plausible results. The proposed Doppler spectral ratio methodology has potential for applications in precipitating snow, liquid and ice clouds and can be extended to other wavelength pairs. Key Points Attenuation and Mie effects ambiguity in dual-wavelength radar techniques Dual-wavelength radar Doppler spectral ratio (DSR) has a quasi-universal shape DSR can help to disentangle the two components of the dual-wavelength ratio ©2013 The Authors. Geophysical Research Letters published by Wiley on behalf of the American Geophysical Union.