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Analysis of cloud top height and cloud coverage from satellites using the O2 A and B bandsCloud height and cloud coverage detection are important for total ozone retrieval using ultraviolet and visible scattered light. Use of the O2 A and B bands, around 761 and 687 nm, by a satellite-borne instrument of moderately high spectral resolution viewing in the nadir makes it possible to detect cloud top height and related parameters, including fractional coverage. The measured values of a satellite-borne spectrometer are convolutions of the instrument slit function and the atmospheric transmittance between cloud top and satellite. Studies here determine the optical depth between a satellite orbit and the Earth or cloud top height to high accuracy using FASCODE 3. Cloud top height and a cloud coverage parameter are determined by least squares fitting to calculated radiance ratios in the oxygen bands. A grid search method is used to search the parameter space of cloud top height and the coverage parameter to minimize an appropriate sum of squares of deviations. For this search, nonlinearity of the atmospheric transmittance (i.e., leverage based on varying amounts of saturation in the absorption spectrum) is important for distinguishing between cloud top height and fractional coverage. Using the above-mentioned method, an operational cloud detection algorithm which uses minimal computation time can be implemented.
Document ID
19950045732
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Kuze, Akihiko
(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Chance, Kelly V.
(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Date Acquired
August 16, 2013
Publication Date
July 20, 1994
Publication Information
Publication: Journal of Geophysical Research
Volume: 99
Issue: D7
ISSN: 0148-0227
Subject Category
Geophysics
Accession Number
95A77331
Funding Number(s)
CONTRACT_GRANT: NAGW-2541
Distribution Limits
Public
Copyright
Other

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