|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
北海道大学地球物理学研究報告 = Geophysical bulletin of Hokkaido University >
第70号 >
地球放射線帯の動径拡散モデルの構築
| Title: | 地球放射線帯の動径拡散モデルの構築 |
| Other Titles: | Development of a radial diffusion model for Earth’s radiation belts |
| Authors: | 小松, 研吾1 Browse this author | | 渡部, 重十2 Browse this author |
| Authors(alt): | KOMATSU, Kengo1 | | WATANABE, Shigeto2 |
| Issue Date: | 15-Mar-2007 |
| Publisher: | 北海道大学大学院理学研究院自然史科学部門（地球物理学） |
| Journal Title: | 北海道大学地球物理学研究報告 |
| Journal Title(alt): | Geophysical bulletin of Hokkaido University |
| Volume: | 70 |
| Start Page: | 85 |
| End Page: | 93 |
| Abstract: | The radiation belts are the region that energetic charged particles are trapped by Earth’s magnetic field. It is well known that the energetic particles flux are varied during geomagnetic disturbances. Many researchers have studied about the flux variation of radiation belt, but the mechanism of the variation has not been understood in detail. A radial diffusion model can reproduce a basic structure of the radiation belts. Radiation belt particles are supplied from the outer boundary of the radiation belt, and the flux is arranged by the balance of intensity of the diffusion and the loss due to pitch-angle scattering. An intensity and a distribution of the electrostatic field and the whistler waves which determine the magnitude of the diffusion and the loss of radiation belt particles are uncertain. Cornwall (1968) derived the radial diffusion coeffcient due to substorm convection electrostatic field. Brautigam and Albert (2000) derived the root mean square of electrostatic field which is a linear function of Kp index from observations. Lyons et al. (1972) calculated the pitch-angle diffusion within the plasmasphere and the lifetime of the particles. Solving the radial diffusion equations using these functions, the slot region is not formed and the flux near the Earth region is too large. Diffusion coeffcient is reduced by 1/100 at L < Lpp, the slot is formed and too much flux injection from outer belt is suppressed. The change of radial diffusion coeffcient at the plasmapause location may affect the structure of radiation belts. |
| Type: | bulletin (article) |
| URI: | http://hdl.handle.net/2115/20425 |
| Appears in Collections: | 北海道大学地球物理学研究報告 = Geophysical bulletin of Hokkaido University > 第70号
|
|
