Investigations of Microphysical Processes in Clouds Using Spectral Cloud Models Coupled with Polarimetric Radar Measurements at Multiple Frequencies

Published: 30 May 2019

The proposed research explicitly links advanced cloud modeling with state-of-the-art scattering computations and dual-polarization radar observations to reproduce the main features of the microphysical structure of mixed-phase, deep convective clouds. The project capitalizes on unique insights from newer American Recovery and Reinvestment Act (ARRA) ARM Oklahoma radar facilities deployed during the ARM Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign. The overarching goal of the proposed research is to improve the treatment of microphysics in cloud models of varying scales by synthesizing spectral bin microphysical models and ARM multifrequency polarimetric radar measurements of various precipitating clouds.
Three main objectives will be addressed in the proposed study. 1. Quantitatively characterize the lifecycle of convective clouds by exploiting the link between cloud microphysics and storm kinematics using spectral cloud models and the new ARM scanning polarimetric radars. 2. Clarify the mechanisms of ice generation in clouds and the role of aerosols in ice microphysics using spectral cloud models, and determine the dominant crystal habits in the ice portions of clouds using polarimetric radar measurements. 3. Understand the complex interactions between cloud particles and how they affect subsequent precipitation production in mixed-phase clouds. This is possible using sophisticated spectral microphysics models and by analyzing the evolution of particle size distributions using polarimetric radar measurements.
The proposed study will enhance our knowledge of microphysics of deep convective clouds which is crucially important for better understanding of large-scale processes and their reproduction in global circulation models. As a result of this study, a cloud model with reliable spectral microphysics will be developed. This will improve representation of microphyiscs in convective and stratiform clouds in models of different scales. Recommendations for improvement of microphysical parametrization of larger-scale models with bulk microphysics will be provided as an outcome of this research project.

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This work was supported by the U.S. Department of Energy’s Office of Science, through the Biological and Environmental Research program as part of the Atmospheric System Research program.