Discrete ordinate solutions of the transport equation for auroral electrons
Presented here is an interpretation of the discrete ordinate method which has been used to solve the transport equation of auroral electrons in the atmosphere, and the accuracy of this method is discussed with different orders of approximations by numerical analysis. The discrete ordinate method is...
| Main Authors: | , |
|---|---|
| Format: | Report |
| Language: | English |
| Published: |
Upper Atmosphere and Space Research Laboratory
1985
|
| Subjects: | |
| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1773 http://id.nii.ac.jp/1291/00001773/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1773&item_no=1&attribute_id=18&file_no=1 |
| Summary: | Presented here is an interpretation of the discrete ordinate method which has been used to solve the transport equation of auroral electrons in the atmosphere, and the accuracy of this method is discussed with different orders of approximations by numerical analysis. The discrete ordinate method is based on an implicit assumption on the angular distribution of electron intensity. The three types of two-stream approximations (single-Gauss, double-Gauss and Eddington's approximations) are characterized by the different assumptions on which each type is based. The error analysis is given on the energy deposition rate and the energy albedo. The double-Gauss 4-stream approximation is found to be practical in obtaining these two quantities with the accuracy within a few percent, whereas the error in the single-Gauss 4-stream approximation amounts to about 20% for the energy albedo. For the energy deposition rate, any of the two-stream approximations for the incident energies of keV regions has the accuracy comparable to that of the calculation without taking electron scattering into account. For the energy albedo, the errors in the two-stream approximations exceed about 30% in the same energy range. |
|---|