An icing product derived from operational satellite data

Geostationary meteorological satellites are ideal for monitoring cloud systems by providing continuous digital multi-spectral imagery of the Earth-atmosphere system in real-time. Data taken every 30 minutes at 4km resolution by the Geostationary Operational Environmental Satellite (GOES-8) are being analyzed for the Atmospheric Radiation Measurement (ARM) program to provide cloud properties over the Southern Great Plains (SGP) of the central United States. The satellite radiances are matched to radiative transfer calculations of water and ice clouds to determine cloud temperature and altitude, optical thickness, effective particle size and phase. Clouds with sufficient optical thickness that are below freezing with pixels determined to be of the water phase indicate icing conditions. Icing conditions are frequently observed in the satellite-derived cloud properties but may also be obscured by higher level ice clouds. The satellite retrievals are being compared and correlated with pilot reports of icing over the ARM SGP domain to develop an icing index based on the satellite-derived cloud properties. The index will indicate 'no icing' in cases there are no thick water clouds below freezing, 'icing' when icing conditions are determined to exist in the satellite retrievals or 'indeterminate' in cases where super-cooled water clouds of sufficient thickness may exist but are obscured by higher level ice clouds. The analyses are being performed for several months in different seasons. Results of the analyses and statistics of the satellite icing index will be presented.