Aurora and auroral particles

• Main Author: Kazuo Makita
• Format: Report
• Language: English
• Published: Takushoku University 1985
• Subjects: Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1758; http://id.nii.ac.jp/1291/00001758/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1758&item_no=1&attribute_id=18&file_no=1

Electron precipitation observed by DMSP is categorized into five fundamental types in relation to its possible sources as follows : (1) Plasma sheet electrons related to discrete auroras and transpolar θ auroras : The energy spectra of this precipitation show a clear peak electron number flux at some energy between 1 to 10keV. (2) Plasma sheet electrons related to diffuse auroras : The characteristics of energy spectra of this kind of precipitation have no clear peak number flux in the energy range from 50eV to 20keV but have high energy tail. (3) Magnetospheric boundary layer electron related to sun-aligned arcs and/or faint arcs : The energy spectra have a clear peak in the electron number flux at about a few hundred eV. (4) Polar cusp electrons related to dayside soft precipitation : The cusp precipitation is characterized by a large electron number flux and is low energy (less that 100eV). (5) Magnetospheric tail lobe electron related to polar rain : The spectra of these electrons are identical in shape with cusp electron but are generally lower in intensity by about 1-2 orders of magnitude. The spatial distribution of these electron precipitation regions depends on the magnitude of geomagnetic activity and on the IMF polarity, and gives us important information about the solar wind-magnetosphere interaction.