83 An overview of several polarimetric signatures within supercells as seen by a mobile, X-band, polarimetric Doppler radar

Tuesday, 27 September 2011
Grand Ballroom (William Penn Hotel)
Jeffrey C. Snyder, Univ. of Oklahoma, Norman, OK; and H. Bluestein, Y. Jung, V. Venkatesh, and S. J. Frasier

The increased amount of data available from a dual-polarized weather radar can help provide important information about thermodynamic and dynamic processes occurring within deep moist convection. For nearly a decade, graduate students and faculty from the University of Oklahoma and the University of Massachusetts – Amherst have used a mobile, polarimetric, X-band Doppler weather radar (UMass XPol) to collect data in supercells, tornadoes, and other severe convective phenomena throughout the central United States. Much of the previously-performed research making use of polarimetric signatures in supercells has used data from fixed-location radars operating at frequencies below X band (e.g. S band and C band). Although the mobile nature of the UMass XPol has allowed for the collection of high-resolution data, there are some significant complications (e.g. resonance effects and attenuation) of collecting and examining data at X band. Several polarimetric signatures currently in literature – such as the ZDR tower and ρHV ring – will be highlighted using UMass XPol data, and two previously-unexamined signatures – the low-reflectivity ribbon and the ρHV depression on the left side of the BWER – will be discussed as well. With advances in multimoment bulk microphysics schemes, high-resolution numerical model are better able to simulate supercell structure and characteristics. The Advanced Regional Prediction System (ARPS) is used with multimoment microphysics and a polarimetric radar emulator to examine supercells in various combinations of CAPE and shear, and these results will be presented
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