Ice clouds microphysical retrieval using millimeter-wavelength Doppler radar observations

Description

A retrieval algorithm designed to estimate the ice cloud microphysical parameters from millimeter-wavelength cloud radar is presented. It uses combined information of radar reflectivity and Doppler velocity supplemented by temperature. The retrieval technique based on the optimal estimation (OE) method provides estimates of the mean mass-weighted diameter of ice particle size distribution and of ice water content. The algorithm follows the new microphysical approach in which the relations that govern the forward model within the OE framework as described in Szyrmer et al. (2012) are developed. The OE iterative technique allows a quantitative evaluation of the uncertainty of the retrieved quantities and is applied separately for a few selected sets of microphysical parameters. The final solution is the one that is most consistent with the radar observables. A sensitivity analysis of the proposed retrieval technique was performed using the cloud radar measurements collected during the SPARTICUS field campaign over the ARM Southern Great Plains site between January and June 2010.