Microphysical and thermodynamic retrievals in deep convective clouds using polarimetric radar measurements and spectral cloud models with explicit treatment of aerosol impact on convective processes (Final Report)

• Main Authors: Ryzhkov, Alexander, Khain, Alexander, Giangrande, Scott
• Language: unknown
• Published: 2021
• Subjects: 54 ENVIRONMENTAL SCIENCES; Arctic
• Online Access: http://www.osti.gov/servlets/purl/1582218; https://www.osti.gov/biblio/1582218; https://doi.org/10.2172/1582218

The final report contains general descriptions of the novel techniques for microphysical and thermodynamic retrievals in clouds and precipitation using polarimetric radars with numerous examples of their applications in different climate regions and seasons including analysis of the land-falling hurricane Harvey. The report also summarizes the results of multiparameter measurements with the ARM and WSR-88D radars of the mesoscale convective systems observed in the US and Europe. Such measurements have been coupled and compared with in situ microphysical observations onboard of a research aircraft during the ARM MC3E field campaign. The synergy between cloud radar polarimetry and Doppler spectral analysis was explored in deep cold precipitation systems in the Arctic using the ARM radars. On a modeling side, a modified version of the spectral bin microphysical scheme, FSBM-2, has been developed and implemented in WRF and its superior performance was demonstrated for the May 20, 2011 mesoscale convective system observed during MC3E. Another effort was focused on the analysis of the sea spray impact on microphysics and dynamics of tropical cyclones. This requires explicit treatment of the size distribution of CCN and its evolution in the WRF / FSBM-2 model. Simulations of hail-bearing storms with this model produce realistic columns of differential reflectivity Zdr which serve as radar proxies of the convective updraft. It was demonstrated that the characteristics of Zdr columns are highly correlated with vertical velocity, hail size, and aerosol concentration.