论文标题
使用IPATH模型对2017年9月10日的太阳能粒子事件进行建模
Modeling the 10 September 2017 solar energetic particle event using the iPATH model
论文作者
论文摘要
2017年9月10日，从活性区域（AR）12673爆发了快速的冠状质量弹出（CME），导致地球上的地面增强（GLE）事件。使用2D改善了在Heliosphere（IPath）模型中的颗粒加速度和运输，我们对2017年9月10日在地球，火星和立体声A中观察到的大型太阳能粒子（SEP）事件进行了建模。基于观察性证据，我们假设CME驱动的冲击发生后不久，在此模拟中以双高斯速度曲线进行建模。我们将原位冲击到达时间以及在地球附近的多个航天器上观察到的CME速度作为约束来调整输入模型参数。然后将建模的时间强度曲线和能量质子的通量与观测值进行比较。发现与MARS和StereoA的观察结果合理的协议。地球上的模拟结果与GOOS-15的观察结果不同。取而代之的是，在地球向西20度的HeliePentric经度下，模拟的结果与GON观察非常吻合。这可以解释，如果地球上的事件前太阳风磁场未由名义帕克田描述。我们的结果表明，由于先前事件引起的CME驱动冲击和扭曲的星际磁场的横向膨胀对于理解这一GLE事件可能很重要。
On September 10 2017, a fast coronal mass ejection (CME) erupted from the active region (AR) 12673, leading to a ground level enhancement (GLE) event at Earth. Using the 2D improved Particle Acceleration and Transport in the Heliosphere (iPATH) model, we model the large solar energetic particle (SEP) event of 10 September 2017 observed at Earth, Mars and STEREO-A. Based on observational evidence,we assume that the CME-driven shock experienced a large lateral expansion shortly after the eruption, which is modelled by a double Gaussian velocity profile in this simulation. We use the in-situ shock arrival times and the observed CME speeds at multiple spacecraft near Earth and Mars as constraints to adjust the input model parameters. The modelled time intensity profiles and fluence for energetic protons are then compared with observations. Reasonable agreements with observations at Mars and STEREO-A are found. The simulated results at Earth differ from observations of GOES-15. Instead, the simulated results at a heliocentric longitude 20 degree west to Earth fit reasonably well with the GOES observation. This can be explained if the pre-event solar wind magnetic field at Earth is not described by a nominal Parker field. Our results suggest that a large lateral expansion of the CME-driven shock and a distorted interplanetary magnetic field due to previous events can be important in understanding this GLE event.
