[P-EM17] 宇宙天気・宇宙気候

[PEM17-15] MHD-SDE Hybrid Simulation of the Cosmic Ray Modulation

*三宅 晶子¹、松本 倫明²、片岡 龍峰^3,9、佐藤 達彦⁴、塩田 大幸⁵、宮原 ひろ子⁶、今田 晋亮⁷、上野 遥⁸ (1.茨城工業高等専門学校、2.法政大学、3.国立極地研究所、4.日本原子力研究開発機構、5.情報通信研究開発機構、6.武蔵野美術大学、7.名古屋大学、8.宇宙航空研究開発機構、9.総合研究大学院大学)

A reliable prediction of the space weather conditions on the radiation exposure caused by galactic cosmic rays (GCRs) is one of challenges topics in the field of space weather forecast. In order to understand heliospheric environments during extremely weak solar cycle such as past grand minima and the current solar cycle, we have developed a hybrid simulation model for the cosmic-ray modulation, which solves the stochastic differential equations (SDEs) describing a propagation of the GCRs in a dynamical MHD model of the heliosphere. We have calculated the dynamical model of the heliosphere with an adaptive mesh refinement technique. Space weather forecast system, SUSANOO, is imposed on the inner boundary of the dynamical model. By considering the solar wind velocity and the heliospheric magnetic field obtained from the dynamical model of the heliosphere, we have calculated the trajectories and the momentum histories of the GCRs that have a charge-sign dependence caused by the drift motion in the heliospheric magnetic field. In this presentation, we will show preliminary results of our MHD-SDE hybrid simulation for the cosmic-ray modulation during recent solar cycle.