Coordinated Analysis of Fully Polarmetric CSU-CHILL Radar Signatures with Surface and Airborne Hydrometeor Images
Coordinated analysis of CSU-CHILL polarimetric radar data and insitu hydrometeor measurements from two instrumented chase vans, airborne imaging probe, and other auxiliary surface observations is proposed for evaluating and improving bulk-hydrometeor classification schemes and precipitation estimation algorithms. The T-28 aircraft equipped with the High Volume Particle Spectrometer (HVPS) obtained high quality hydrometeor images in three convective storms and one bright-band event during a deployment in June 1995. One chase van was instrumented with the 2D-video disdrometer obtained on lease from Joanneum Research, Graz, Austria. Numerous storm cell intercepts were made with this van providing high quality image data (front and side views, vertical speed) in intense rain mixed at times with hail. During the 1996/97 winter season, the disdrometer was located for one period at the CSU campus site, and for another period at the NCAR Marshall field site where a variety of winter precipitation was sampled in conjunction with other auxiliary measurements (snow gauge, formvar replication). A second chase van was equipped with a roof-mounted hail catcher net (of NCAR design) and a capacitance rain gauge. Numerous hail intercepts were made enabling the determination of time-resolved hail rates and size distributions. Recently developed optimal area algorithms which address the problem of comparing radar measurements aloft with surface instruments will be further refined and evaluated. This proposal seeks funding for a comprehensive analysis of these insitu hydrometeor data to advance polarimetric-based hydrometeor classification schemes and more fully evaluate polarimetric rainrate algorithms in mixed phase precipitation.
