Validation of simulated hurricane drop size distributions using polarimetric radar

• Published in: Geophysical research letters 2016-01, Vol.43 (2), p.910-917
• Main Authors: Brown, Bonnie R., Bell, Michael M., Frambach, Andrew J.
• Format: Article
• Language: English
• Subjects: Computer simulation; Hurricane tracking; Hurricanes; Mathematical models; Meteorology; Microphysics; numerical modeling; Parametrization; Radar; Radar signatures; Spectra; Tropical cyclones
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2015GL067278

Recent upgrades to the U.S. radar network now allow for polarimetric measurements of landfalling hurricanes, providing a new data set to validate cloud microphysical parameterizations used in tropical cyclone simulations. Polarimetric radar reflectivity and differential reflectivity simulated by the Weather Research and Forecasting model were compared with real radar observations from 2014 in Hurricanes Arthur and Ana. Six different microphysics parameterizations were tested that were able to capture the major features of both hurricanes, including accurate tracks, precipitation asymmetry, and the approximate intensity of the storms. A high correlation between simulated intensity and rainfall across schemes suggests an intimate link between the latent heating produced by the microphysics and the storm dynamics. Most of the parameterizations produced a higher frequency of larger raindrops than observed. The Thompson aerosol‐aware bulk and explicit spectral bin microphysical schemes showed the best fidelity to the observations at a higher computational cost. Key Points Hurricanes Arthur and Ana (2014) are simulated to test WRF microphysical schemes Simulated polarimetric radar signatures are validated with new observations Spectral bin and Thompson bulk schemes compare best with the radar observations