Long-term Vertical Air Velocity and Precipitation Parameter Retrievals in Rainfall from 95-GHz Doppler Radar Spectra

Edward Luke Brookhaven National Laboratory
Scott Giangrande Brookhaven National Laboratory
Pavlos Kollias McGill University

Category: Cloud Properties

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Time vs. height plot of vertical air velocity during one hour of stratiform rain at Niamey, Niger.

In recent years, the ARM Mobile Facility (AMF) has been deployed for continuous measurement collection over extended periods at several climatologically distinct locations, including Niamey, Niger, and Germany's Black Forest. AMF deployments include a vertically-pointing 95-GHz cloud radar (WACR), a tool of choice for profiling non-precipitating clouds at high spatial and temporal resolutions. In this study, we demonstrate the utility of the WACR for retrievals of vertical air motion and additional precipitation parameters using techniques that capitalize on non-Rayleigh resonance features in the observed Doppler spectra. The WACR retrieval technique has been automated and applied to an extensive set of stratiform and convective rain events over the Niamey and Black Forest AMF deployments. The dataset includes in excess of 165 hours within light to moderate rainfall. The vertical structure of mean air motion and its associated variances have been extracted for both deployments and reflect the unique differences between an orographic versus desert monsoonal climate. It is anticipated that bulk velocity and precipitation statistics will be valuable for future climate model evaluation. Velocity retrievals are estimated to be accurate to within a range of 5 to 20 cm/s.

This poster will be displayed at ARM Science Team Meeting.

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