Space Plasma Physics, Magnetospheric Physics
The space of our solar system is filled by tenuous and hot plasma, the solar wind. Dynamic variations of the solar activity affect the Earth and planetary environment through the solar wind. Phenomena which occur in the space plasma driven by the solar activity are quite attractive research objects because such space plasma phenomena remind us that the Earth and planets are living with a star, the Sun.
Nowadays, many satellites, including the newest Japanese geospacer explorer “Arase (ERG),” fly and form a multi-point observatory network of space plasma phenomena in the near-Earth space, and the understandings of the space plasma phenomena in geospace are making great progress by using these modern datasets. Also, a Mercury explorer, BepiColombo, which is developed under the Europe-Japan joint project, was launched and is cruising toward Mercury, so that multiple spacecraft fleet in the inner heliosphere are going to be realized by the middle of the 2020s. Such an unprecedented situation must not be missed. Making use of these opportunities, we would like to contribute to solving the mystery of space plasma physics.
A unique advantage of space plasma observations by satellites and explorers is that we can directly access the detailed in-situ information, what happens in space plasma at a point, unlike solar physics and astrophysics whose observation method is limited to remote sensing. Taking advantage of our observations, we can achieve various unique results on space plasma physics.
However, even if we are obtaining full datasets of multi-point measurements in the solar system plasma, the information is still limited, and it is difficult to fully understand various space plasma phenomena those occur in vast space. To compensate for the lack of observations, we believe that numerical simulations are powerful tools, and we are also focusing on researches by numerical simulations. We have achieved important results on elementary processes, like collisionless shock and magnetic reconnection, which are possible to be directly compared with spacecraft observations, by using high-performance supercomputers.
Based on the ideas noted above, we are challenging to understand various complicated space plasma phenomena using both data analysis and numerical simulations as well as operating our spacecraft.
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2. Shinohara, I., M. Fujimoto, T. Nagai, S. Zenitani, and H. Kojima (2016), "Low-Frequency Waves in the Tail Reconnection Region", in Low-Frequency Waves in Space Plasmas (eds A. Keiling, D.-H. Lee and V. Nakariakov), John Wiley & Sons, Inc, Hoboken NJ., doi:10.1002/9781119055006.ch11
3. Shinohara, I., M. Fujimoto, R. Takaki, and T. Inari (2011) "A three-dimensional particle-in-cell simulation of quasi-perpendicular shock on Fujitsu FX1 cluster", IEEE Transactions on Plasma Science 39, 1173-1179, doi:10.1109/TPS.2011.2106515