3-D electrostatic and electromagnetic ray tracing in the magnetosphere

• Main Authors: Kimiya Yamaashi, Kozo Hashimoto, Iwane Kimura
• Format: Report
• Language: English
• Published: Department of Electrical Engineering II, Kyoto University 1987
• Subjects: Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2165; http://id.nii.ac.jp/1291/00002165/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2165&item_no=1&attribute_id=18&file_no=1

A three-dimensional (3-D) ray tracing computer program has been developed, which is applicable to both electrostatic and electromagnetic mode waves, using the hot plasma dispersion relation. This program is able to deal with, for example, a mode conversion process of a wave through propagation in an inhomogeneous medium, such as a smooth conversion from the electrostatic electron cyclotron harmonic mode to the electromagnetic (R-X-Z) mode in a hot plasma. For a sufficiently large wave number region, the electrostatic approximation is also used to trace ray paths. This approximation is, for example, useful to investigate the necessary initial conditions for the mode conversion from the electrostatic mode to the electromagnetic mode. This approximation clarifies that the electron cyclotron harmonic mode waves can propagate over a long distance if the starting point is in a very vicinity of the geomagnetic equator and the wave normal direction is almost perpendicular to the geomagnetic field line. For the mode conversion, the inital wave normal vector must be almost in the meridian plane in addition to the above conditions.