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.
Evidence of Time-Dependent Diffusive Shock Acceleration in the 2022 September 5 Solar Energetic Particle Event
University of Michigan（密歇根大学）；Lunar and Planetary Laboratory, University of Arizona（亚利桑那大学月球与行星实验室）；California Institute of Technology（加州理工学院）；NASA Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；Applied Physics Laboratory, Johns Hopkins University（约翰斯·霍普金斯大学应用物理实验室）；Princeton University（普林斯顿大学）；Southwest Research Institute（西南研究所）
Parker Solar Probe observations of solar energetic particle (SEP) events with inverse velocity arrival (IVA) features
California Institute of Technology（加州理工学院）；Space Sciences Laboratory, University of California, Berkeley（加州大学伯克利分校空间科学实验室）；NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；Princeton University（普林斯顿大学）
Modeling the evolution and propagation of the 2017 September 9th and 10th CMEs and SEPs arriving at Mars constrained by remote-sensing and in-situ measurement
