0000000000046681
AUTHOR
Michael A. Box
Quadrature effects on the accuracy of flux calculations in realistic atmospheres
Abstract We have investigated the accuracy of five different quadrature methods—equal steps in θ, equal steps in cos θ, Gaussian, double Gaussian and Gauss-Lobatto—on the accuracy of fluxes in realistic aerosol atmospheres, using the Gauss-Seidel method. In addition, a range of Gaussian quadrature stream numbers from two to 32 were compared. The atmospheric models considered are those recently presented by Lenoble, with the exception that we have used Henyey-Greenstein phase functions in place of Mie. Our results should be easily reproduceable by any other workers interested in similar realistic atmospheres. A table of Gauss-Lobatto weights and points is provided as an appendix.
Actinic Flux and Net Flux Calculations in Radiative Transfer—A Comparative Study of Computational Efficiency
Abstract The accuracy and speed of three well-known computational techniques (DISORT, the δ–four-stream approximation, and the two-stream approximation), and the matrix inversion method, which is less well known, have been investigated. Results are presented for both broadband actinic and net fluxes over a range of parameters including solar zenith cosine, relative humidity, and altitude for two different surface/aerosol systems: terrestrial and oceanic. The matrix inversion method can only calculate actinic fluxes; therefore, this is the main focus of this paper. Investigations into the comparative accuracy of the four techniques for the oceanic model with and without a cloud layer include…