P5.15
Global daytime and nighttime frequencies of cloud thermodynamic phase as a function of cloud temperature using MODIS data
Richard A. Frey, CIMSS/Univ. of Wisconsin, Madison, WI; and B. A. Baum, S. L. Nasiri, W. P. Menzel, S. A. Ackerman, and L. Gumley
The algorithms currently employed by the MODIS atmospheres team to retrieve cloud height and cloud thermodynamic phase depend solely on infrared (IR) bands and operate independently of each other. Cloud heights are derived using bands located in the 15-mm CO2 band using an approach called the CO2 slicing method. Cloud thermodynamic phase is inferred using an IR technique based on spectral measurements at 8.5 and 11 um. The physical principles behind the determination of each of these atmospheric products will be described, together with examples of their application using global daytime and nighttime MODIS measurements. We will present global results of cloud thermodynamic phase (ice, water, mixed phase, uncertain) as a function of cloud temperature for selected days from each season. Among the statistics detailed will be a preliminary estimate of the global frequency of super-cooled water clouds.
Poster Session 5, New Technology and Methods
Wednesday, 17 October 2001, 2:15 PM-4:00 PM
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