講演情報
[PEM10-P13]Ionospheric role in the development of the M-I convection system: generation of Alfvénic disturbances from the ionospheric convection field deformed by conductance non-uniformity
*中溝 葵1、吉川 顕正2、中田 裕之3、深沢 圭一郎4、田中 高史5 (1.情報通信研究機構 電磁波研究所、2.九州大学大学院理学研究院、3.千葉大学大学院工学研究院、4.京都大学学術情報メディアセンター、5.九州大学国際宇宙惑星環境研究センター)
キーワード：
磁気圏電離圏結合、磁気圏MHDシミュレーション
We investigate how the ionosphere affects the magnetosphere by using a global magnetosphere MHD model.
First, we perform the simulation with the widely used conventional M-I coupling scheme.
We simulate the uniform and non-uniform ionospheric Hall conductance distribution cases. By using the Walén Separation [Yoshikawa et al., 2011], we separate the simulated disturbance field into the components propagating into/away from the inner boundary (Alfvénic disturbances). In the cases of non-uniform Hall conductance, the Alfvénic disturbances propagate dawn-dusk asymmetrically between the magnetosphere and ionosphere, resulting the dawn-dusk asymmetric magnetospheric convection field, including a Harang-like structure.
The result indicates that the ionosphere plays an active role in the configuration and dynamics of the global magnetosphere due to its non-uniform conductance distribution, as suggested by Nakamizo and Yoshikawa [2019].
In order to precisely investigate the role of the ionosphere, we are implementing an advanced M-I coupling scheme, Alfvénic Coupling [Yoshikawa et al., 2010] into the MHD model. We will show the results of the new coupling and compare them with that of the conventional coupling.
First, we perform the simulation with the widely used conventional M-I coupling scheme.
We simulate the uniform and non-uniform ionospheric Hall conductance distribution cases. By using the Walén Separation [Yoshikawa et al., 2011], we separate the simulated disturbance field into the components propagating into/away from the inner boundary (Alfvénic disturbances). In the cases of non-uniform Hall conductance, the Alfvénic disturbances propagate dawn-dusk asymmetrically between the magnetosphere and ionosphere, resulting the dawn-dusk asymmetric magnetospheric convection field, including a Harang-like structure.
The result indicates that the ionosphere plays an active role in the configuration and dynamics of the global magnetosphere due to its non-uniform conductance distribution, as suggested by Nakamizo and Yoshikawa [2019].
In order to precisely investigate the role of the ionosphere, we are implementing an advanced M-I coupling scheme, Alfvénic Coupling [Yoshikawa et al., 2010] into the MHD model. We will show the results of the new coupling and compare them with that of the conventional coupling.