Extended Abstract (92K)P4.11
Using CloudSat data to validate icing products
Cory A. Wolff, NCAR, Boulder, CO; and T. F. Lee, C. Mitrescu, S. D. Landolt, and S. D. Miller
CloudSat is part of the A-Train, a group of polar orbiting remote sensing instruments launched to provide detailed views of clouds and the atmosphere. It carries a cloud radar that gives a two-dimensional vertical profile of cloudy areas without any information about the cloud phase.
The NCAR Current and Forecast Icing Products (CIP/FIP) produce diagnoses and forecasts, respectively, of the probability and severity of aircraft icing conditions aloft over the CONUS and southern Canada. The CIP and FIP algorithms include schemes for identifying cloud tops and bases along with distinct cloud layers. These are based on model data only in FIP and a combination of model data with observations from satellite and surface stations in CIP. Validation of these schemes has been difficult in the past because of a lack of observational truth data. Cloud tops and bases and information on cloud layers are seldom reported by pilots, and existing reports can be unreliable.
CloudSat provides regular observations of cloud layers that can be used to validate these schemes in CIP and FIP. Both algorithms tend to be overly conservative in cloud top estimation, resulting in higher cloud tops than those observed and a greater volume of icing-warned airspace than needed. More accurate cloud tops will reduce the volume of icing produced, which increases the efficiency of the algorithms and decreases the amount of overforecasting. Better representation of cloud layers will have the same effects, giving a better picture of clear spaces embedded in icing-prone clouds. This improvement can also improve diagnoses and forecasts of the vertical extent of precipitation, which can have a large effect on the diagnosed icing conditions. Early results of these comparisons will be presented along with ideas for performing quantitative studies.
Poster Session 4, Radar and Icing Posters
Thursday, 24 January 2008, 9:45 AM-11:00 AM, Exhibit Hall B
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