JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Oral

P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM14] [EE] Dynamics in magnetosphere and ionosphere

Sat. May 20, 2017 3:30 PM - 5:00 PM 105 (International Conference Hall 1F)

convener:Tomoaki Hori(Graduate school of Science, University of Tokyo), Yoshimasa Tanaka(National Institute of Polar Research), Aoi Nakamizo(Applied Electromagnetic Research Institute, National Institute of Information and Communications Technology), Mitsunori Ozaki(Faculty of Electrical and Computer Engineering, Institute of Science and Engineering, Kanazawa University), Chairperson:Motoharu Nowada(Shandong University), Chairperson:shun Imajo(Kyushu Univ.)

3:45 PM - 4:00 PM

[PEM14-07] Magnetosphere-Ionosphere coupling process produced by Ampere force forcing from the magnetosphere

*Akimasa Yoshikawa1 (1.Department of Earth and Planetary Sciences, Kyushu University)

Keywords:Magnetosphere-Ionosphere Coupling, Ampere force forcing, dynamical polarization process

The way of M-I coupling process through Ampere force forcing from the magnetosphere to the ionosphere is discussed. There are many kinds of electromagnetic coupling ways between magnetosphere and ionosphere, e.g.,
1. FAC forcing: map the FAC distribution from the magnetosphere to the ionosphere and calculate ionospheric electrostatic electric field (production of FAC-free polarization field),
2. Electric field forcing: map the electric field distribution from the magnetosphere to the ionosphere and calculate the FAC distribution at the ionosphere (production of polarization-free FAC distribution).
However, as discussed by Yoshikawa et al., [2010], both of above ways cannot simultaneously satisfy energy and current conservation. Alternatively the way of M-I coupling through shear Alfven wave can do that in local coupling. On the other hand, Alfvenic-coupling with electrostatic approximation cannot provide physical mechanism how a localized Alfvenic coupling phenomenon drives global ionbospheric current system.
In this study, we propose a new way of M-I coupling theory that formulating the M-I coupling process as subsequent process of ion dynamics produced by the Ampere force forcing from the magnetosphere, that is, 3. Ampere force forcing: map the Ampere force from the magnetosphere to the ionosphere and calculate ionospheric flow through the force balance equation, induced electric field through the generalized Ohm’s law, a new magnetic field perturbation through Faraday’s induction law, new current density through Ampere’s law, and new Ampere’s force as a result of this coupling process can feed back to the magnetosphere.
Some example of M-I coupling process, aurora streamer, WTS evolution during substorm process, and dynamical Cowling channel formation will be discussed.