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

[PEM14-15] Response of the Earth’s magnetosphere and ionosphere to the small-scale magnetic flux rope in solar wind by the MHD simulation

*Kyung Sun Park¹、Myeong Joon Kim¹、Dae-Young Lee¹、Kyungsuk Cho²、Rok Soon Kim²、Tatsuki Ogino³ (1.Chungbuk National University, Korea、2.Korea Astronomy and Space Science Institute, Korea、3.ISEE, Nagoya University, Japan)

キーワード：small-scale magnetic flux rope, magnetosphere and ionosphere , cross polar cap potential

We have studied the response of the Earth’s magnetosphere and ionosphere to two cases of small-scale magnetic flux ropes in solar wind by using a three-dimensional global MHD simulation. (1) the case of +Z axis of magnetic flux rope, the IMF is northward with a dawn to dusk B_Y components as right-handed, (2) the case of +Y axis of magnetic flux rope, the IMF is north to southward with a duskward B_Y as right-handed and solar wind dynamic pressure is normal (1.3 nPa).
The simulation results show that the bow shock is located at about 14.6 R_E and the magnetopause is located at about 10.24 R_E in both cases. However, ionospheric phenomena show the different feature for two cases. The cross polar cap potential becomes small during the northward even though magnitude of magnetic field becomes large for +Z axis of magnetic flux rope. And the cross polar cap potential increase that is governed by magnitude of magnetic field as well as southward B_Z for +Y axis of magnetic flux rope.