A Unified Understanding of the Earth's Radiation Environment

对地球辐射环境的统一认识

• 批准号: NE/Z000157/1
• 负责人: Sarah Glauert
• 金额: $ 126.28万
• 依托单位: British Antarctic Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FZ000157%2F1
• 关键词: Unified; Understanding; Earth; Radiation; Environment

Our society is increasingly reliant upon technological infrastructure that orbits in the harsh and highly dynamic radiation environment of near-Earth space. Low-cost access to space is driving a rapid increase in the number of satellites on orbit (e.g., Starlink, Oneweb), many of which use electronics that are untested during active solar conditions, such as the upcoming solar maximum in 2024-2025. This proposal will make a significant advance in the understanding of the radiation environment in which these satellites operate.Space was a £16.5 Bn UK industry in 2019/2020 and severe space weather was added to the National Risk Register in 2011, owned by the Met Office who provide space weather services to the satellite industry. However, current forecasting models, including the BAS Radiation Belt Model (BAS-RBM) that provides forecasts to the Met Office and European Space Agency, only forecast the highest energy electrons and the associated risk of damage from internal charging. The Met Office currently has no capability to forecast the lower energy electrons that can cause surface charging damage and be energised to become so-called 'killer' electrons.The radiation environment is highly dynamic and includes several different populations of electrons, identified by their energy ranges. The lowest energy electrons form the background plasma, medium energy electrons are found in the ring current, and the highest energy electrons form the radiation belts. These have historically been studied independently but the populations are interdependent, and recent research has highlighted that they need to be studied as a single system. For example, the highest energy killer electrons are produced when lower energy electrons are energised by electromagnetic waves. These waves are generated by the medium energy electrons and the acceleration is most effective in regions with a depleted background plasma. This proposal aims to establish how the populations and their interactions contribute to the variability of the radiation environment. We will determine which solar wind conditions produce the most effective wave-electron interactions, quantify the role of realistic magnetic fields on the loss and energisation of electrons, and determine how the interactions of the different populations affect the radiation environment in key types of space weather events. This will significantly increase our understanding of the conditions that lead to radiation environments that may damage satellites.These studies require a combination of data analysis and modelling. A few models can study multiple populations, but they all initially addressed a single population using an appropriate framework for that population. Extending to include another population meant incorporating an additional framework, introducing interpolation errors and inconsistencies. For example, although these models use realistic magnetic field models for part of the calculation, they assume a dipole magnetic field to model the wave-electron interactions. Building on our BAS-RBM experience, we will adopt a novel approach using a unifying framework for all three populations that can also include realistic magnetic and electric fields. To be consistent we will also develop the first comprehensive characterisations of wave-electron interactions in realistic magnetic fields. Using observations from spacecraft such as the Van Allen Probes, together with this new modelling framework, we will address the causes of variability in the radiation environment. The model created for these studies will also be able to provide improved predictions of the conditions leading to internal charging on satellites and a new ability to address surface charging.

我们的社会越来越依赖于技术基础设施，这些技术基础设施在近地空间的危害和高度动态的辐射环境中轨道。低成本进入太空正在驱动轨道上的卫星数量迅速增加（例如，Starlink，OneWeb），其中许多使用在主动太阳能条件下未经测试的电子设备，例如即将到来的太阳能最大值，即2024 - 2025年。该提案将在对这些卫星运行的辐射环境中的理解中取得重大进步。空间在2019/2020年为16.5亿英镑的英国行业，并在2011年的国家风险登记册中增加了严重的太空天气，该登记册由众议员办公室拥有，该机构为卫星行业提供了太空天气服务。但是，当前的预测模型，包括为MET办公室和欧洲航天局提供森林的BAS辐射带模型（BAS-RBM），仅预测最高的能源电子设备以及内部充电造成的损害风险。 MET办公室目前没有能力预测较低的能量电子产品，这些电子电子可能会导致表面充电损坏并能够成为所谓的“杀手”电子设备。辐射环境具有高度动态性，包括通过其能量范围确定的几种不同的电子群体。最低的能量电子形成背景等离子体，中型能电子设备在环电流中发现，最高能量电子形成了辐射带。从历史上看，这些都是独立研究的，但人口是相互依存的，最近的研究强调，它们需要研究为单个系统。例如，当较低的能量电子通过电子波能源能源时，产生最高的能量杀手电子。这些波是由中型能电子产生的，并且在具有耗尽的背景等离子体的区域中，加速度最有效。该建议旨在确定人口及其相互作用如何促进辐射环境的变异性。我们将确定哪些太阳风条件会产生最有效的波电子相互作用，量化现实磁场对电子损耗和能量的作用，并确定不同种群的相互作用如何影响空间天气事件类型的辐射环境。了解导致辐射环境可能会损害卫星的条件。这些研究需要组合数据分析和建模。一些模型可以研究多个人群，但最初使用适当的框架为该人群解决了一个人群。扩展到其他人群意味着编码一个额外的框架，引入插值错误和不一致。例如，尽管这些模型使用逼真的磁场模型作为计算的一部分，但它们假设一个偶极磁场来对波电子相互作用进行建模。在我们的BAS-RBM体验的基础上，我们将使用一种统一的框架为所有三个人群采用一种新颖的方法，这些框架也可以包括现实的磁场和电场。为了保持一致，我们还将发展在逼真的磁场中波电子相互作用的第一个综合特征。使用航天器（例如van allen探针）的观察以及这个新的建模框架，我们将解决辐射环境中可变性的原因。为这些研究创建的模型还将能够改善对导致卫星内部充电的条件的预测，并具有新的解决表面充电能力。