Presentation PDF (177.5 kB)
In situ measurements of cloud top properties in icing conditions are essential for evaluating the efficacy of satellite- and radar-derived cloud and icing products. The Improvement of Microphysical Parameterization through Observational Verification Experiment (IMPROVE) provided an array of in-situ observations suitable for assessment of remote sensing techniques. Here we examine three cases from IMPROVE-2, conducted in west central Oregon during the fall of 2001. Satellite, aircraft, and radar measurements are employed for detection and characterization of aircraft icing conditions. In two of the cases, supercooled liquid was encountered by the research aircraft. A third case, in which a completely glaciated cloud was observed, was selected in order to test the retrieval algorithms in a non-icing situation.
Results show general consistency between the remote and in situ measurements. Cloud thermodynamic phase derivations from GOES-12 and AVHRR/3 algorithms suggest a combination of mixed- and liquid-phase conditions in the two cases where icing conditions were observed the aircraft. Radar-derived particle identification (PID) fields are also compared with aircraft in situ and satellite measurements. Ice crystals and irregular ice crystals are the primary particle type detected in the two cases where icing was observed by the aircraft. Due to the mixed-phase conditions, only a few radar pixels indicate the presence of liquid droplets. In the third case, satellite and radar retrievals indicate ice-phase particles exclusively, as was observed by aircraft in situ measurements. Detailed results and algorithm descriptions will be provided at the conference.