日本地球惑星科学連合2019年大会

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[J] 口頭発表

セッション記号 P (宇宙惑星科学) » P-CG 宇宙惑星科学複合領域・一般

[P-CG25] 惑星大気圏・電磁圏

2019年5月28日(火) 10:45 〜 12:15 A05 (東京ベイ幕張ホール)

コンビーナ:関 華奈子(東京大学大学院理学系研究科)、今村 剛(東京大学大学院 新領域創成科学研究科)、前澤 裕之(大阪府立大学大学院理学系研究科物理科学科)、寺田 直樹(東北大学大学院理学研究科)、座長:中川 広務(東北大学 大学院理学研究科 地球物理学専攻太陽惑星空間物理学講座 惑星大気物理学分野)、関 華奈子(東京大学大学院理学系研究科地球惑星科学専攻)

11:00 〜 11:15

[PCG25-06] A Novel High-Moment Multifluid Model for Mercury: From the Planetary Conducting Core to the Dynamic Magnetosphere

*Chuanfei Dong1Liang Wang1Ammar Hakim1Amitava Bhattacharjee1James A Slavin2Gina A DiBraccio3Kai Germaschewski4 (1.Princeton University、2.University of Michigan, Ann Arbor、3.NASA Goddard Space Flight Center、4.University of New Hampshire)

キーワード:Mercury's dynamic magnetosphere, ten-moment multifluid model, induction effect, tightly coupled interior-magnetosphere system, collisionless magnetic reconnection, extreme events

We have developed a novel three-dimensional ten-moment multifluid model and applied it to investigate the tightly coupled interior-magnetosphere system of Mercury. This new multifluid model self-consistently solves the continuity, momentum and pressure tensor equations of each species, together with the full Maxwell equations. As a result, non-ideal effects including the Hall effect, inertia, and tensorial pressures are self-consistently embedded without the need for explicitly solving a generalized Ohm's law.

Our simulation results from this new model are in good agreement with observations from MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. The model is able to reproduce the magnetic field vectors, field-aligned currents and cross-tail current sheet asymmetry observed by MESSENGER. We also investigate collisionless magnetic reconnection in Mercury's magnetotail and at dayside magnetopause. In addition, we study the magnetospheric response of Mercury to a hypothetical extreme event with an enhanced solar wind dynamic pressure, which demonstrates the significance of electromagnetic induction effects resulting from the coupled interior. Moreover, two plasmoids (or flux ropes) are formed in Mercury's cross-tail current sheet during this hypothetical extreme event, indicating the extremely dynamic nature of Mercury's magnetotail. Thus, this novel high-moment, multifluid, interior-magnetosphere-coupled model is crucial for understanding Mercury's dynamic magnetosphere and has the potential to enhance the science returns of both the MESSENGER and BepiColombo missions.