講演情報
[PEM09-P10]Soft X-Ray Imaging of the Earth's High-latitude Reconnection Region Under Northward Interplanetary Magnetic Fields
*百瀬 遼太1、松本 洋介2、三好 由純3 (1.千葉大学大学院融合理工学府、2.千葉大学国際高等研究基幹、3.名古屋大学宇宙地球環境研究所)
The charge exchange between high charge-state ions in the solar wind and the Earth's exosphere (geocorona) emits soft X-rays. This emission process, termed SWCX (Solar Wind Charge eXchange), is useful for visualizing the dayside magnetosphere and its response to solar wind variations. The SMILE and GEO-X missions have been proposed to provide soft X-ray images of the magnetosheath and cusps and will contribute to a better understanding of the dynamic response of the Earth's magnetosphere.
For this purpose, we have developed a global magnetohydrodynamic simulation model of the magnetosphere (Matsumoto and Miyoshi, 2022). The model can provide three-dimensional distributions of the soft X-ray intensity from the plasma parameters. Then line-of-sight integrations of the intensity distribution give a two-dimensional X-ray map as a virtual observation in the simulation domain. Therefore, simulation runs under different solar wind conditions allow us to understand how the global intensity map reflects the magnetospheric dynamics. We studied 2D X-ray maps under northward interplanetary magnetic field conditions seen from a high-latitude spacecraft orbit. We found that virtual observations successfully identified the shape of the high-latitude magnetopause. Furthermore, we found that under low plasma-β solar wind conditions, the X-ray intensity can reflect the bulk motion of outflows from the high-latitude reconnection region. This particular observation will give great opportunities to visually understand the spatial extent of the high-latitude magnetic reconnection.
For this purpose, we have developed a global magnetohydrodynamic simulation model of the magnetosphere (Matsumoto and Miyoshi, 2022). The model can provide three-dimensional distributions of the soft X-ray intensity from the plasma parameters. Then line-of-sight integrations of the intensity distribution give a two-dimensional X-ray map as a virtual observation in the simulation domain. Therefore, simulation runs under different solar wind conditions allow us to understand how the global intensity map reflects the magnetospheric dynamics. We studied 2D X-ray maps under northward interplanetary magnetic field conditions seen from a high-latitude spacecraft orbit. We found that virtual observations successfully identified the shape of the high-latitude magnetopause. Furthermore, we found that under low plasma-β solar wind conditions, the X-ray intensity can reflect the bulk motion of outflows from the high-latitude reconnection region. This particular observation will give great opportunities to visually understand the spatial extent of the high-latitude magnetic reconnection.