講演情報
[PPS05-P02]Observations and Test Particle Simulations of Low-energy Ions in Mercury's Magnetosphere
*原田 裕己1、斎藤 義文2、Hadid Lina3、Delcourt Dominique3、相澤 紗絵3、Rojo Mathias4、André Nicolas4、Persson Moa4、Fraenz Markus5、横田 勝一郎6、Fedorov Andréi4、三宅 亙7、Penou Emmanuel4、Barthe Alain4、Sauvaud Jean-André4、Katra Bruno3、松田 昇也8、村上 豪2 (1.京都大学、2.ISAS, JAXA、3.LPP-CNRS-Sorbonne Université-Ecole Polytechnique、4.IRAP, CNRS-UPS-CNES、5.Max-Planck-Institute for Solar System Research、6.大阪大学、7.東海大学、8.金沢大学)
キーワード：
水星、磁気圏、ベピ・コロンボ
Mercury's magnetosphere represents arguably the most strongly solar wind-driven magnetosphere among the intrinsic magnetospheres in the solar system. In particular, the magnetospheric circulation at Mercury is expected to be completely dominated by solar wind-driven convection as opposed to corotation because of the intense solar wind in the inner heliosphere, the planet's slow rotation rate, and the absence of a conducting ionosphere. Despite its importance, the magnetospheric convection at Mercury remains poorly characterized by observations due to the lack of adequate measurements of cold plasma velocities and DC electric fields.
BepiColombo Mio observations during the first three Mercury flybys reveal the ample presence of low-energy (<100 eV/q) ions as well as their variability presumably caused by variable upstream solar wind conditions. Here we attempt to give an interpretation of the sources and transport of the low-energy ions based on a comparison of the Mio observations with test particle simulations. We also discuss the implications of the results for the plasma transport and plasma-surface interactions in this extreme case of the solar wind-driven magnetosphere.
BepiColombo Mio observations during the first three Mercury flybys reveal the ample presence of low-energy (<100 eV/q) ions as well as their variability presumably caused by variable upstream solar wind conditions. Here we attempt to give an interpretation of the sources and transport of the low-energy ions based on a comparison of the Mio observations with test particle simulations. We also discuss the implications of the results for the plasma transport and plasma-surface interactions in this extreme case of the solar wind-driven magnetosphere.