AGS-PRF: An Observational-based Modeling Approach for Solar Energetic Particle Access to the Equatorial Inner Magnetosphere

关于太阳高能粒子(SEP)如何与地磁场相互作用，仍有许多问题。这些粒子在发生爆炸事件后流入地磁环境，如太阳耀斑和日冕物质抛射。粒子可能会被困在地磁场中，这些粒子的能量以及地球空间环境，包括目前的系统，都会影响它们穿透的距离。这一博士后奖学金支持对这一主题的研究，这对于了解空间天气对卫星等敏感系统的影响非常重要，因为卫星可能会受到SEPS的破坏。除了支持早期职业科学家，该项目还包括创建空间天气演示，将用于教育推广活动。将采用基于观测的综合建模方法，提供对SEP进入地磁场的影响的统计洞察。这项研究利用了20个太阳高能粒子事件，这些事件发生在2013年1月至2017年12月期间的一系列风暴和非风暴条件下，并通过至少两颗卫星进行了测量。使用多航天器方法，观测将同时在各种径向距离、能量和一系列磁性当地时间进行检查。利用在磁层内观测到的太阳质子的东西向通量各向异性，有可能测量近赤道地区的粒子截止值。他们将把现场测量的能量和方向相关的截止值与通过使用粒子跟踪模型计算的地磁截止值进行比较。使用Tsyganenko 2005粒子示踪模型，他们将确定哪些当前系统有助于抑制地磁中断。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Many questions remain about how solar energetic particles (SEPs) interact with the geomagnetic field. These particles stream into the geomagnetic environment following explosive events, such as flares and coronal mass ejections from the Sun. Particles may become trapped in the geomagnetic field and the energy of these particles as well as the geospace environment, including current systems, affect how far they penetrate. This postdoctoral fellowship supports research on this topic, which is important to understanding space weather impacts to sensitive systems like satellites, which can be damaged by SEPs. In addition to supporting an early career scientist, this project includes the creation of a space weather demonstration that will be used in educational outreach events.A comprehensive observational-based modeling approach will be employed to provide statistical insights into what processes affect SEP access into the geomagnetic field. The study utilizes 20 solar energetic particle events, which occur during a range of storm and non-storm conditions, from January 2013-December 2017, and which are measured with at least two satellites. Using a multi-spacecraft approach, the observations will be examined at a wide variety of radial distances, energies, and at a range of magnetic local times simultaneously. Utilizing the east-west directional flux anisotropy for solar protons observed in the inner-magnetosphere it is possible to measure particle cutoffs in the near-equatorial region. They will compare the energy and directional dependent cutoffs measured in-situ to the geomagnetic cutoffs calculated via the use of particle tracking models. Using the Tsyganenko 2005 particle tracing model they will determine which current systems contribute to suppressed geomagnetic cutoffs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.