11:00 〜 11:15
[PEM15-08] GEO-Xミッションに向けた磁気圏グローバルMHDシミュレーションモデルの開発
キーワード：磁気圏MHDシミュレーション、ジオコロナ、GEO-Xミッション
In-situ observations by space crafts have revealed plasma dynamics in the terrestrial magnetosphere in response to the solar wind variations. They have provided ample opportunities to understand plasma kinetics in space and astrophysical phenomena where energy release and dissipation by the magnetic reconnection, collision-less shocks, and turbulence are of great interest. After many decades of the in-situ measurement era, GEO-X (Geospace x-ray imager) mission has been proposed by introducing the x-ray imaging technologies in astrophysics to visualize intermediate to global structures of the magnetosphere. The GEO-X project measures charge exchange emissions between oxygen ions in the solar wind and hydrogen atoms from the Earth's atmosphere (geocorona). The x-ray emission strength is strongly dependent on the solar wind oxygen ion distribution around the magnetosphere. Therefore it is crucial to model the global ion density distribution under various solar wind conditions to design the project and understand observational data.
We have developed a global MHD simulation model of the magnetosphere by using the public MHD code CANS+ (Matsumoto+19) as a successor to the GEMSIS-GM model (Matsumoto+10). CANS+ is a shock-capturing, high-resolution MHD code. It has been applied to accretion disks around the black hole (Igarashi+20) and astrophysical jet propagations (Ohmura+20;21). The code is hybrid-parallelized and effectively runs on massively parallel supercomputer systems. We adopted this code to develop the magnetospheric model. For this purpose, we modified the base equation by subtracting the potential field (dipole magnetic field) component from the magnetic field (Miyoshi+10). To maintain the magnetic field's solenoidal property, we introduced the projection method (Brackbill & Barnes80) in addition to the hyperbolic divergence cleaning method (Dedner+02) to manage substantial divergence errors around the inner boundary located at five Earth radii. In this talk, we report the current status of the development and the model's detailed algorithms.
We have developed a global MHD simulation model of the magnetosphere by using the public MHD code CANS+ (Matsumoto+19) as a successor to the GEMSIS-GM model (Matsumoto+10). CANS+ is a shock-capturing, high-resolution MHD code. It has been applied to accretion disks around the black hole (Igarashi+20) and astrophysical jet propagations (Ohmura+20;21). The code is hybrid-parallelized and effectively runs on massively parallel supercomputer systems. We adopted this code to develop the magnetospheric model. For this purpose, we modified the base equation by subtracting the potential field (dipole magnetic field) component from the magnetic field (Miyoshi+10). To maintain the magnetic field's solenoidal property, we introduced the projection method (Brackbill & Barnes80) in addition to the hyperbolic divergence cleaning method (Dedner+02) to manage substantial divergence errors around the inner boundary located at five Earth radii. In this talk, we report the current status of the development and the model's detailed algorithms.