A spherical-shell radiative transfer model for the calculation of limb radiances
AuthorLoughman, Robert Paul, 1971-
AdvisorHerman, Benjamin M.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractA new spherical-shell radiative transfer model has been developed, with particular emphasis on the accurate calculation of the scattered radiance in the limb of the atmosphere. The model accounts for the spherical geometry of the atmosphere for all orders of scattering, but neglects the influence of polarization and refraction. Solutions are obtained by the successive orders of scattering method for several solar zenith angles simultaneously, using the inherent symmetry of the radiation field about the sub-solar point. The model is described by comparing and contrasting it with the model previously presented by Thome (1990) and Herman et al. (1994). The new model is tested against independent calculations to demonstrate the accuracy of the method. Its results are compared with the Monte Carlo calculations presented by Adams and Kattawar (1978) and Kattawar and Adams (1978) for a homogeneous atmosphere. Agreement is observed to within the stated statistical error of the Adams and Kattawar (1978) and Kattawar and Adams (1978) results for all lines of sight, including those in the limb. Comparisons are also made to the results obtained by the Herman et al. (1994) code for a more realistic atmospheric profile. These comparisons reveal excellent agreement outside the limb of the atmosphere, but some significant disagreement in the limb, which must be investigated further. Finally, preliminary results are presented that demonstrate the sensitivity of limb scattered radiances to changes in the ozone profile. Limb radiances are shown to be sensitive to a relatively small change in the ozone abundance in a thin layer of the atmosphere. However, the observed sensitivity is shown to decrease when aerosol scattering is added to the model atmosphere.
Degree ProgramGraduate College