Evaluation of the Microphysics of Precipitation with Multifrequency Radar Observations (EMPORiuM)

Several recent studies stressed the critical impact of rain drop size distribution (DSD) parameterization on the whole evolution of frontal systems simulated with cloud resolving models using two-moment microphysics schemes. For example, the latent heat release through evaporation depends heavily on the drop breakup efficiency and impacts the dynamics of the system and the total precipitation at the ground. The lack of observed profiles of the drop size distribution prevented further constraints on the parameterizations of the DSD and drop breakup.

A novel technique based on new observations from dual-frequency (35 and 94 GHz) profiling radars is able to provide profiles of binned DSD at very high vertical and temporal resolution for rain rates comprised between 1 and 30 mm/h. Such observations are unprecedented and can supply the necessary information to improve the simulations.

This prospective project will investigate on a case study how these observations can be used to improve the realism of the simulation of precipitation microphysics. First comparisons between the retrieved and modelled DSD properties will be presented for a squall line moving over Oklahoma and captured by the ARM radars at the SGP central facility on the 12 June 2011.