The deltaSobolev approach for modeling solar spectral irradiance and radiance
Abstract
The development and evaluation of a solar radiation model is reported, which gives irradiance and radiance results at the bottom and top of an atmosphere of specified optical depth for each of 145 spectral intervals from 0.29 to 4.05 microns. Absorption by water vapor, aerosols, ozone, and uniformly mixed gases; scattering by molecules and aerosols; and nonLambertian surface reflectance are included in the model. For solving the radiative transfer equation, an innovative deltaSobolev method is developed. It applies a deltafunction modification to the conventional Sobolev solutions in a way analogous to the deltaEddington method. The irradiance solution by the deltaSobolev method turns out to be mathematically identical to the deltaEddington approximation. The radiance solution by the deltaSobolov method provides a convenient way to obtain the directional distribution pattern of the radiation transfer field, a feature unable to be obtained by most commonly used approximation methods. Such radiance solutions are also especially useful in models for satellite remote sensing. The model is tested against the rigorous Dave model, which solves the radiation transfer problem by the spherical harmonic method, an accurate but very time consuming process. Good agreement between the current model results and those of Dave's model are observed. The advantages of the deltaSobolev model are simplicity, reasonable accuracy and capability for implementation on a minicomputer or microcomputer.
 Publication:

Ph.D. Thesis
 Pub Date:
 1990
 Bibcode:
 1990PhDT.........1X
 Keywords:

 Approximation;
 Delta Function;
 Irradiance;
 Mathematical Models;
 Radiance;
 Radiative Transfer;
 Solar Radiation;
 Solar Spectra;
 Spectral Reflectance;
 Microcomputers;
 Minicomputers;
 Optical Thickness;
 Satellite Observation;
 Scattering;
 Surface Properties;
 Solar Physics