09:15 〜 09:30
[PEM10-02] Circulation and acceleration of ionosphere outflow O+ ions through upstream solar wind region driven by an IMF discontinuity: 3D global hybrid simulation
キーワード：ionosphere outflow, O+ ions, IMF discontinuity, ring current, circulation and acceleration
Based on the predictions of global 3D hybrid simulations, we present a new transport/acceleration path for escaped ionosphere outflow O+ ions in the upstream solar wind region resulting from the impact of a particular IMF tangential discontinuity (TD) with negative (positive) IMF Bz on the discontinuity’s anti-sunward (sunward) side. For O+ ions escaping to the duskside magnetosheath and with gyro-radii larger than the TD thickness, when they encounter the TD, they can first go sunward into the upstream solar wind. They then gyrate clockwise to the pre-noon side and get accelerated within the solar wind region and circulate back to the dawnside magnetosphere. These ions may be accelerated to well within the ring current energy range (~30 to 100s of keV) depending on the solar wind electric field strength. This new transport/acceleration path can bring some of the escaped ions into the inner magnetosphere, thus providing a new mechanism for generating an O+ ring current population.