GEM: Diffuse and Discrete Auroral Electron Precipitation Effects On Magnetosphere-Ionosphere Coupling

极光，也就是俗称的北极光，在太阳发出的磁场扰动期间，在地球天空中显示出动态、明亮的光。极光是一种重要的空间天气现象，它将太空中距离地球很远的地方发生的事情与我们的大气联系起来。在磁场干扰的情况下，沉淀或降落到天空中的电子会产生这些明亮的光。析出的电子是大气层的能量来源，可引起社会和国家空间安全关切的空间天气影响。例如，来自沉淀电子的能量的重新分配可能影响对卫星在大气层中的轨道的预测和/或对航天器返回地球的位置的预测。拟议的研究活动将有助于改进对非常复杂的极光电子沉淀效应的科学理解和建模。研究成果将有助于NSF支持的更广泛的地球空间环境建模(GEM)社区工作，以推进空间天气模型。它使两名代表性不足的女科学家能够从事将对国家空间安全问题产生积极影响的基础研究。该项目将包括对职业生涯早期的女科学家的职业指导，以及对航空航天公司不同的本科生实习生的研究培训，这对于支持多样性、公平性和融入下一代空间科学家和工程师至关重要。这项提议的目的是更好地了解弥散和离散极光电子沉淀对磁层-电离层(MI)电动力耦合的作用。这些科学问题是：(问题1)在磁暴期间，极光扩散电子降水如何通过电动力学MI耦合影响极光电离层电导率、高度积分电导、场向电流以及电离层和磁层内电场？磁学和电学自洽处理粒子传输和损失，包括弥散极光降水，能解释风暴期间观测到的电导(PFISR)、场向电流(安培)和电场(PFISR、DMSP、Van Allen探测器)吗？(SQ2)在磁扰动期间，与地区性离散极光电子沉淀有关的电离层电导率和高度积分电导是多少？叠加的弥散和局域离散极光电子沉淀对磁层内电场和粒子输运有什么影响？为了处理SQ1，将使用三个模型的耦合：(1)磁电自洽赖斯对流模型-平衡(RCM-E)，计算由于波-粒子相互作用的影响而产生的内部磁层粒子输运和降水；(2)超热电子输运(STET)模型，将修改RCM-E沉淀电子通量以包括共轭半球之间的后向散射和多次反射的影响；(3)B3C极光输运模型的结果，计算电导率的垂直分布。为了解决SQ2问题，参数化高斯极光电子分布将与STET和B3C模型一起使用来计算电离层电导率。将使用地面测光仪和所有天空成像数据等观测数据来约束综合电子能量通量，并将离散极光降水的平均能量参数化。将进行模拟，以包括与离散极光相关的电导和与更广泛扩散极光重叠的局部区域中的电势降，以调查对内部磁层粒子传输的影响。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。

The aurora, also commonly known as the Northern lights, display dynamic, brilliant lights in the Earth’s sky during magnetic disturbances that emanate from the sun. The aurora is an important space weather phenomenon that links what is happening much farther away from the Earth in space to our atmosphere. During magnetically disturbed conditions, electrons that precipitate or rain down into the sky cause these brilliant lights. The precipitating electrons are a source of energy to the atmosphere and can cause space weather effects that are of concern to society and national space security. For example, the redistribution of energy from the precipitating electrons can affect predictions of orbits of satellites in the atmosphere and/or predictions of the location of re-entry of spacecraft back to Earth. The proposed research activities will lead to improved scientific understanding and modeling of the very complex auroral electron precipitation effects. The research outcomes will contribute to a broader NSF-supported community effort of Geospace Environment Modeling (GEM) for advancing space weather models. It enables two underrepresented female scientists to engage in fundamental research that will positively impact national space security concerns. The project will involve career mentoring of an early career female scientist and research training of diverse undergraduate student interns at The Aerospace Corporation that are vital for supporting diversity, equity, and inclusion in the next generation of space scientists and engineers. The objective of this proposal is to understand better the role of diffuse and discrete auroral electron precipitation on magnetosphere-ionosphere (MI) electrodynamic coupling. The science questions are (SQ1) How does diffuse auroral electron precipitation affect the auroral ionospheric conductivity, height-integrated conductance, field-aligned currents, and the ionospheric and inner magnetospheric electric field through the electrodynamic MI coupling during magnetic storms? Can a magnetically and electrically self-consistent treatment of the particle transport and loss, including diffuse auroral precipitation, account for observed conductance (PFISR), field-aligned currents (AMPERE), and electric fields (PFISR, DMSP, Van Allen Probes) during storms? (SQ2) What are the ionospheric conductivity and height-integrated conductance associated with representative discrete auroral electron precipitation in localized regions during magnetic disturbances? What are the effects of the superimposed diffuse and localized discrete auroral electron precipitation on the inner magnetospheric electric field and particle transport? To address SQ1, a coupling of three models will be used: (1) the magnetically and electrically self-consistent Rice Convection Model-Equilibrium (RCM-E) that calculates inner magnetospheric particle transport and precipitation due to the effect of wave-particle interactions, (2) the Superthermal Electron Transport (STET) model that will modify the RCM-E precipitating electron fluxes to include the effects of backscatter and multiple reflections between conjugate hemispheres, and (3) results from the B3C auroral transport model that computes altitudinal profiles of conductivity. To address SQ2, parameterized representative Gaussian auroral electron distributions will be used with STET and the B3C model to compute ionospheric conductivity. Observations such as ground-based photometers and All Sky Imaging data will be used to constrain the integrated electron energy flux, and the average energy of the discrete auroral precipitation will be parameterized. Simulations will be performed to include the conductance and potential drops associated with the discrete aurora in a localized region overlapping the broader diffuse aurora to investigate the effects on the inner magnetospheric particle transport.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.