JpGU-AGU Joint Meeting 2017

講演情報

[EE]Eveningポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

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

2017年5月20日(土) 17:15 〜 18:30 ポスター会場 (国際展示場 7ホール)

[PEM14-P24] Study of polar cap potential saturation using global MHD simulation: Difference between steady and unsteady state

*久保田 康文1長妻 努1田 光江1藤田 茂2中溝 葵1田中 高史3 (1.情報通信研究機構、2.気象大学校、3.九州大学)

The cross polar cap potential (CPCP) is a value of the convection cycle strength of a solar wind-magnetosphere-ionosphere (SW-M-I) system via Region-1 FAC. CPCP shows an almost linear relationship with the solar wind merging electric field, but it tends to be saturated when the merging electric field becomes large. Siscoe et al. [2002], by using global MHD simulation, suggested that the CPCP basically depends on solar wind electric field, dynamic pressure and ionospheric conductivity. They also suggested that CPCP saturation results from the fact that the solar wind dynamic pressure limits the amount of Region-1 FAC. Their discussion is based on steady state of simulation results, however, in actual cases, solar wind and ionosphere conductivity vary with time and accordingly the state of SW-M-I system should be changed. The purpose of this study is to investigate the cause of the CPCP saturation for time varying condition. In this presentation we will discuss the difference of CPCP saturation between steady and unsteady states.