Ice in Convective Storm Environments: Assessing the Impacts of Microphysics on Simulated Reflectivities

Satellite radar retrievals of clouds and precipitation rely on assumptions about the microphysical properties of hydrometeors such as particle size distributions (PSDs) and mass–dimensional relationships, which have been shown to vary in distinct environments. A deeper understanding of linkages between mass–dimensional relationships, ice crystal shape, and radar reflectivities across cloud and precipitation regimes is necessary for developing new retrievals for upcom-ing satellite radar missions, including the Investigation of Convective Updrafts (INCUS), as well as future missions that will feature space-borne radars observing clouds, convection, and precipitation. This study investigates ice microphysical characteristics through aircraft in situ and remote sensing observations from two convective events during the Midlatitude Continental Convective Clouds Experiment (MC3E) in the Southern Great Plains and tests implications for ice particle habit in forward-modeled radar observations. During MC3E, the Ka/Ku-band High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) was on board the NASA ER-2 aircraft, while in situ measurements were taken on board the University of North Dakota Citation. In situ PSDs and particle shape information from optical array probe data are used to forward model radar reflectivities from particle scattering databases and are compared against HIWRAP reflectivities. Various particle combinations can be used to find agreement with HIWRAP observations, and the forward-modeled reflectivities were sensitive to particle type. Varying the riming on the aggregate and graupel particles resulted in larger than 10-dB differences in reflectivities. The in situ and radar observations imply the occurrence of aggregation, size sorting, and lofting particles.