Path-Length Distributions of Photons Diffusely Reflected from a Semi-Infinite Atmosphere

Abstract

view Abstract Citations (7) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Path-Length Distributions of Photons Diffusely Reflected from a Semi-Infinite Atmosphere Appleby, John F. ; Irvine, William M. Abstract Knowledge of the probability distribution of photon path lengths for diffuse reflection in the continuum from a planetary atmosphere greatly simplifies computation of the shape and strength of absorption lines formed under conditions of multiple scattering. Graphs of this probability distribution are presented for diffuse reflection from a semi-infinite conservative atmosphere for both isotropic and forward-directed scattering, and for several angles of incidence and reflection. Graphs showing distributions for the case of absorption in the continuum are also discussed. The distributions are obtained from an analytic expression for the path-length distribution for nthorder scattering and a tabulation of nth-order intensities. It is found that the shape of the probability distribution depends markedly on the degree of forward scattering due to the phase function. The results are compared with those obtained by a Monte Carlo computation of the sort which might be used if tabulated nth-order intensities were not available. The method appears to hold considerable promise for the rapid computation of reflection spectra, including problems with complex geometries. Subject headings: atmospheres, planetary - radiative transfer Publication: The Astrophysical Journal Pub Date: July 1973 DOI: 10.1086/152230 Bibcode: 1973ApJ...183..337A full text sources ADS |