Analysis and Modeling of the Data from CubeSat: Colorado Student Space Weather Experiment (CSSWE)

地球周围的电子辐射环境是航天资产的主要危害。理解它，理想地达到对其对太阳风驱动条件变化的反应进行预测建模的程度，是磁层物理学的中心目标。在任何给定时间，辐射带的状况是近地环境中作用于粒子的能量和损耗过程之间微妙平衡的结果。这两者目前都没有得到很好的理解。该项目将使用由美国国家科学基金会资助的立方体卫星任务的新测量结果，该任务最近与数值模拟一起进行，以确定高能电子损失率。只有准确地确定损失率，才有可能全面地模拟辐射带动力学。科罗拉多学生空间天气实验（CSSWE）是一个小型的，所谓的立方体卫星，由美国国家科学基金会资助，作为美国国家航空航天局的次要有效载荷发射到高倾角，低空轨道。2012年9月，中国启动了“纳米卫星教育发射”计划。整个CSSWE系统，包括其地面站，由学生设计、建造、校准、测试、交付和操作，并由科罗拉多大学大气与空间物理实验室的教师和专业工程师提供指导和帮助。卫星工程远远超过了它？它已经收集了近地轨道上高能电子和质子超过12个月的高质量数据。根据该合同进行的先进数据分析将继续利用这一独特的数据集，反过来，将有助于最大限度地提高这一已经非常成功的立方体卫星项目的科学投资回报。在大多数情况下，科学调查是为研究生设计的，并将由研究生在PI和合作者的监督下进行。迄今为止，外辐射带电子的降水损失率还没有被量化和解决。目前发表的论文中的电子损失率是不稳定的，并且有一个数量级的差异。本研究的目标是通过先进的建模，直接从数据中量化降水损失及其对经度、L和MLT的依赖，从而为研究界在这一重要问题上提供定量的答案。具体来说，这项工作将与NASA范艾伦探测器一起分析一年多的CSSWE数据，以确定电离层在逐渐衰减、快速损失和大量增加期间的损失率。分析逐渐损失期间的CSSWE数据将确定在此期间需要多少额外的能量来维持辐射带；分析快速损耗期间的数据将确定有多少损耗是由散射到电离层造成的，有多少损耗是由向外径向扩散造成的；分析大增益期间的损耗将决定需要多少额外的能量来产生所观察到的电子通量增益。这种降水损失对辐射带电子整体动力学的影响将通过比较CSSWE的测量结果以及相应的建模结果与范艾伦探测器在同一时间和地点的测量结果来评估。

The electron radiation environment around Earth is a major hazard to spaceflight assets. Understanding it, ideally to the point of predictive modeling of its response to changing solar wind driving conditions, is a central goal of magnetospheric physics. The condition in the radiation belts at any given time is the result of a delicate balance between energization and loss processes operating on the particles in the near-Earth environment. Neither of these is well understood at present. This project will use new measurements from a NSF-funded CubeSat mission that was recently carried out together with numerical modeling to determine the energetic electron loss rate. Only when the loss rate is accurately determined will it be possible to fully model the radiation belt dynamics. The Colorado Student Space Weather Experiment (CSSWE) is a tiny, so-called CubeSat, satellite mission funded by NSF and launched into a high inclination, low-altitude orbit as a secondary payload under NASA?s Educational Launch of Nanosatellites (ELaNa) program in September 2012. The entire CSSWE system, including its ground station, was designed, built, calibrated, tested, delivered, and operated by students, with mentoring and help provided by faculty and professional engineers at the Laboratory for Atmospheric and Space Physics at University of Colorado. The satellite project far exceeded it?s expected life-time and has collected more than 12 months worth of high quality data on energetic electrons and protons in Low-Earth-Orbit. The advanced data analysis to be done under this award will continue the exploitation of this unique dataset and, in turn, will help to maximize the scientific return on investment of this already highly successful CubeSat project. For the most part, the scientific investigation is designed for and will be carried out by graduate students under the supervision of the PI and collaborators. To date, the precipitation loss rate of the outer radiation belt electrons has not been quantified and resolved. The electron loss rates in current published papers are erratic and diverge by an order of magnitude. The goal of this study is to quantify the precipitation losses and their dependence on longitude, L, and MLT directly from the data with advanced modeling, thus providing a quantitative answer to the research community on this important issue. Specifically, this effort will analyze over a year's worth of CSSWE data in conjunction with the NASA Van Allen Probes to determine the loss rates into the ionosphere during periods of gradual decay, during episodes of fast loss and during episodes of large gain. Analyzing CSSWE data during periods of gradual loss will determine how much additional energization occurs during such periods to maintain the radiation belts; analyzing the data during periods of fast loss will determine how much of the loss occurs by scattering into the ionosphere versus loss due to outward radial diffusion; analyzing the loss during periods of large gains will determine how much additional energization is needed to produce the observed gains in electron flux. The impact of such precipitation loss to the overall dynamics of radiation belt electrons will then be assessed by comparing the measurements of CSSWE and the corresponding modeling results with measurements from the Van Allen Probes at the same times and locations.