<title>Cirrus clouds millimeter-wave reflectivity comparison with in-situ ice crystal airborne data</title>

In an effort to evaluate scattering models for particle size distributions of ice crystals within cirrus clouds, simultaneous data was collected during the Department of Energy (DoE) Atmospheric Radiation Measurement (ARM) Cloud Intensive operational period (Cloud IOP) at the Cloud and Radiation Testbed (CART) site in Lamont, Oklahoma, from the NCAR Video Ice Particle Sampler (VIPS) and UMass 33GHz/95GHz Cloud Profiler Radar System (CPRS) in March 2000. Data collected simultaneously from both sensors was used to retrieve and compare the equivalent radar reflectivity at Ka band (33GHz). The equivalent reflectivity is measured by the ground-based, zenith- looking, CPRS radar at Ka band and compared to the reflectivity computed from the airborne VIPS samples of particle size distribution, N(D), using Mie theory. In addition, equivalent reflectivity was calculated with ice particles model of bullet rosettes shaped crystals developed with DDSCAT software and compared with the Mie (sphere shape) results. "Results from the two sensors data sets compare the equivalent reflectivity obtained with the bullet rosettes model as opposed to the sphere model for ice particles. (change this when actual results are found"