Vertical Air Motion Retrieval from Frequency-Modulated Continuous-Wave-Radar Rain Measurements

Vertically pointing S-band Doppler radars measure reflectivity-velocity spectra, where the falling velocity of raindrops appears as a shift along the velocity axis. However, in convective rain scenarios, vertical air motion (VAM) introduces errors into radar-derived products, including drop size distribution, rain rate, and reflectivity factor. This study presents an enhanced forward-model retrieval method for estimating VAM velocity and retrieving these radar products. The forward estimator employs a parameterized Gamma distribution and an unknown VAM velocity to estimate the radar-observed aliased reflectivity-velocity profile. Building on previous work by the authors, this paper introduces a mathematical formulation for the aliased radar reflectivity along with first application of the method to a real measurement case from VORTEX-SE 2017 campaign.