8 April 1988 Cloud Cover Statistics Using VAS
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Proceedings Volume 0874, Nonlinear Optical Beam Manipulation, Beam Combining, and Atmospheric Propagation; (1988) https://doi.org/10.1117/12.943862
Event: 1988 Los Angeles Symposium: O-E/LASE '88, 1988, Los Angeles, CA, United States
Statistics of cloud characteristics over North. America have been calculated for the past two years. The frequency of cloud cover with the associated heights and infrared attenuation were charted using the CO2 channel radiometric data from the geostationary VISSR Atmospheric Sounder (VAS). Cloud top pressures were determined from the ratio of VAS CO2 channel radiances in a radiative transfer equation formulation. Cloud emissivities were then calculated from infrared window channel observations. CO techniques derived height and emissivity assignments have been found to be reliable in all cloud types, including thin cirrus clouds where other techniques have been inconsistent. Observations since 1985 revealed that 25% to 35% of the United States was covered with thin clouds (radiative attenuation was less than 95%), 45% was covered with thick opaque clouds, and 20% to 30% had clear sky conditions. Geographical distribution of cloud cover shows a latitudinal dependence mainly over the Pacific Ocean. Moderate seasonal and diurnal changes were also found.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
D P Wylie, D P Wylie, W P Menzel, W P Menzel, } "Cloud Cover Statistics Using VAS", Proc. SPIE 0874, Nonlinear Optical Beam Manipulation, Beam Combining, and Atmospheric Propagation, (8 April 1988); doi: 10.1117/12.943862; https://doi.org/10.1117/12.943862


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