ANSWERS: Understanding and Forecasting Solar Energetic Particles in the Inner Solar System and Earth's Magnetosphere

太阳上的爆发事件，如太阳耀斑和日冕物质抛射（cme），可以极大地激发电子、质子和重离子。当这些“太阳高能粒子”（sep）与地球相互作用时，它们是潜在的太空天气危害。它们会对航空电子设备、卫星和宇航员产生不利影响。预测SEP事件是一个挑战，因为它们是不可预测的，粒子可以在太阳事件的几分钟到几小时内到达地球。为了减轻由于sep对我们这个依赖技术的社会的有害影响，我们需要彻底了解这种高能粒子是如何在太阳系中运输和加速的，特别是在近地空间。由于问题的性质和规模，这样的理解需要来自多个学科的研究人员的合作努力，包括太阳物理、空间物理和地球空间科学、等离子体物理和粒子物理。在这个项目中，来自亨茨维尔阿拉巴马大学（UAH）、密歇根大学（UM）、威斯康辛大学（River Falls）和美国国家太阳天文台的多学科团队将开发一个全面的科学模型来理解和预测SEPs。他们将创建一个基于网络的SEP预报工具，由UAH和UM托管，供空间气象界使用。大学生和博士后研究员将在项目的各个方面发挥领导作用。因此，这项前沿研究工作的更广泛影响在于，它有可能提高社会对空间天气灾害的抵御能力，同时提高我国在空间科学和空间天气方面的专业知识。该项目将建立一个全面的科学模型，以了解和预测cme如何影响内太阳系和地球磁层的高能粒子辐射环境，并将结果与地球表面的测量结果进行比较。两个广泛使用的模式，空间天气模式框架（SWMF）和改进的粒子加速和输运在日光层模式（iPATH）将耦合。SWMF和iPATH的现有空白将通过开发两个新模型来弥补：一个是用于太阳下日冕的机器学习辅助CME模型，另一个是用于从拉格朗日L1点进入磁层的粒子追踪模型。综合模型将提供模拟从CME发射到地面中子监测器探测到的信号的sep传播的能力，并解释对星系宇宙射线的影响，例如Forbush衰减。模型验证将包括在太阳周期23和24期间与若干地面增强和大型SEP事件的中子监测数据进行比较。一个综合的SEP/GCR预报工具将通过网络界面向空间天气界开放。每日预报L1点和磁层内的SEP/GCR通量，以及每8小时提供一次中子监测仪通量（如适用）。鉴于人们对太阳-地球系统科学的兴趣日益浓厚，澳大将开设一门研究生水平的磁层物理学课程。本科生和研究生以及包括博士后学者在内的早期职业研究人员将全面参与研究和推广工作。ANSWERS项目将通过填补有关太阳-地球耦合系统的关键知识空白，提高美国的STEM专业知识和社会对空间天气灾害的适应能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Eruptive events on the Sun such as solar flares and coronal mass ejections (CMEs) can greatly energize electrons, protons and heavy ions. When these "solar energetic particles" (SEPs) interact with the Earth, they are a potential space weather hazard. They can have adverse impacts on avionics, satellites, and astronauts. Forecasting SEP events is a challenge because they are unpredictable and the particles can arrive at Earth within minutes to hours of the solar event. To mitigate the harmful effects due to SEPs on our technology-dependent society, we need a thorough understanding of how such energetic particles are transported and accelerated in the solar system, particularly in near-Earth space. Due to the nature and scale of the problem, such an understanding requires collaborative efforts from researchers in multiple disciplines, including solar physics, space physics and geospace sciences, plasma physics and particle physics. In this project, a multidisciplinary team from the University of Alabama in Huntsville (UAH), University of Michigan (UM), University of Wisconsin at River Falls, and the National Solar Observatory will develop a comprehensive scientific model to understand and forecast SEPs. They will create a web-based SEP forecasting tool hosted by UAH and UM for use by the space weather community. University students and a postdoctoral researcher will have leadership roles in all aspects of the project. The broader impacts of this cutting-edge research effort are thus in its potential to improve societal resilience to a space weather hazard while advancing our nation's expertise in space science and space weather. This project will develop a comprehensive scientific model to understand and predict how CMEs influence the energetic particle radiation environment in the inner solar system and Earth's magnetosphere, and compare the results with measurements at the Earth's surface. Two widely used models, the Space Weather Modeling Framework (SWMF) and the improved Particle Acceleration and Transport in the Heliosphere model (iPATH) will be coupled. Existing gaps in SWMF and iPATH will be bridged by developing two new models: a machine learning-assisted CME model for the lower solar corona, and a particle tracing model for transport from the Lagrange L1 point into the magnetosphere. The integrated model will provide the ability to simulate the propagation of SEPs from CME launch to signals detected by ground-based neutron monitors, and account for effects on galactic cosmic rays, e.g., the Forbush decrease. Model validation will include comparison with neutron monitor data for a number of ground level enhancements and large SEP events during solar cycles 23 and 24. An integrated SEP/GCR Forecasting Tool will be made openly accessible to the space weather community through a web interface. Daily forecast of the SEP/GCR flux at the L1 point and inside the magnetosphere, as well as neutron monitor flux (when applicable) will be provided at 8-hour intervals. Given the increased interest in Sun-Earth system science, a graduate level course on magnetospheric physics will be developed at UAH. Undergraduate and graduate students and early-career researchers including a postdoctoral scholar will be fully involved in the research and outreach efforts. ANSWERS projects will advance the nation’s STEM expertise and societal resilience to space weather hazards by filling key knowledge gaps regarding the coupled Sun-Earth system.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.