Attenuation correction and hydrometeor classification of high-resolution, X-band, dual-polarized mobile radar measurements in severe convective storms

The dynamics of severe convective storms depend, to some extent, on the distribution and type of hydrometeors within the storm. In order to estimate the three-dimensional distribution of hydrometeors using X-band radar data, it is necessary to correct for attenuation before applying commonly used hydrometeor classification algorithms. A mobile, dual-polarization Doppler weather radar designed at the University of Massachusetts – Amherst has been used since 2002 to collect high-resolution data in severe convective storms in the central United States. This study examines the results of attenuation correction using dual-polarization measurements in supercells and tornadoes with varying degrees of attenuation collected between 2004 and 2009, and comparisons to nearby WSR-88Ds (both single-polarization and the dual-polarization KOUN radar) are noted where available. After correcting for attenuation and differential attenuation, a fuzzy logic hydrometeor classification algorithm, modified for X-band with KOUN data as a reference, is used to attempt a classification of hydrometeor types in observed severe convective storms. Hydrometeor classification and retrievals of various aspects of the drop-size distribution of high-resolution radar data in close proximity to supercells and tornadoes may elucidate the dynamic and thermodynamic processes of the production of cold pools in supercells, as well as provide a form of verification to which numerical models can be compared.