SHINE: Solar Energetic Particles Mediating Interplanetary Shocks Close to the Sun

太阳高能粒子(SEP)是一种高能粒子，可以从太阳一路传播到地球表面，这可能会对通信系统造成重大破坏。它们的产生机制仍然是一个有很大争议的话题，强烈的日冕和星际不连续或日冕物质抛射(CME)驱动的激波可能是原因之一。以前的观测研究了从地球轨道到外日光层不同太阳距离的这些激波，但仅限于地球轨道以外的距离(1 Au)。然而，目前帕克太阳探测器(PSP)和太阳轨道器(SOLO)的观测使我们能够通过探测1Au以下的广泛距离来构建更完整的图像。研究这一区域的一个关键结果是，这些现场观测将提供SEP和冲击波测量，随着航天器逐渐接近太阳，SEP和冲击波测量受运输效应的影响大大减少。PSP和SOLO的数据将在这些航天器观测到SEP强度异常高的冲击事件时进行分析。这些结果将解决太阳附近激波对高能粒子加速的重要问题，以及这些粒子如何影响这些年轻激波的结构。此外，由于高能粒子介导的激波预计将在广泛的时空尺度上发生在各种天体物理环境中，我们对非常接近太阳的这种结构的全面搜索可能从根本上有助于我们理解众所周知的由宇宙射线介导的无碰撞激波。该项目的科学目标是(1)量化SEP介导的休克，(2)评估SEP对休克中介的影响，以及(3)探索休克-SEP之间的关系。该项目将支持一名职业生涯早期的女科学家和APL巡回计划的一名本科生参与该项目，该项目将促进研究和教育。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。

Solar energetic particles (SEPs) are high-energy particles that can propagate from the Sun all the way to the surface of the Earth, which can cause significant disruptions to communication systems. Their generation mechanisms remain a subject of much debate, with strong coronal and interplanetary discontinuities or shocks driven by coronal mass ejections (CME) being likely responsible. Previous observations studied these shocks at different solar distances from the Earth’s orbit to the outer heliosphere, but were limited to distances mostly outside the Earth’s orbit (1 au). Currently, however, observations with Parker Solar Probe (PSP) and Solar Orbiter (SolO) allow us to build a more complete picture by probing extensively distances below 1 au. A key consequence of studying this region, which is the goal of this project, is that these in-situ observations will provide SEP and shock measurements that are dramatically less affected by transport effects as the spacecraft progressively get closer to the Sun.The data from PSP and SolO will be analyzed for periods when these spacecraft observe shock events with exceptionally high SEP intensities. The results will address the significant issue of energetic particle acceleration by shocks near the Sun and how the particles affect the structure of these young shocks. Additionally, as energetic-particle-mediated shocks are predicted to occur in various astrophysical settings across a broad range of spatial and temporal scales, our comprehensive search for such structures very close to our Sun may fundamentally contribute to our understanding of well-known ‘cosmic ray’-mediated collisionless shocks. The science goals of this project are to (1) quantify SEP-mediated shocks, (2) assess SEP impact on shock mediation, and (3) explore shock-SEP relationships. This project will support an early-career female scientist and an undergraduate student from the APL CIRCUIT Program to work on this project which will be promoting research and education.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.