High-Resolution 3-D Simulations of the Thermospheric Response to Magnetic Storms, Substorm Surges and the Diffuse Aurora

研究人员将研究E区中性热层对极光强迫增强的反应。特别是，其目的是解释和理解在黎明和黄昏恢复阶段观察到的现象、扩散极光、以及热层对膨胀相涌动的反应以及在大型磁暴期间观察到的新现象。这些专题涉及对空间物理学和大气学领域具有重要意义的领域，而这些领域的知识有限。以前的工作需要使用三维(3-D)、高分辨率、非静力、成分相关的模式来模拟热层对黎明扇区漫射极光的响应。该模型能够在与ARIA(极光大气响应)火箭测量相同的高度范围内，再现黎明扇区弥漫极光区域和切变下方不稳定区域中的非常强的切变。先前研究项目的结果表明，除了地磁强迫外，传播的潮汐模式对观测到的结构的产生也起着重要作用。在这项研究中，研究人员将使用3-D高分辨率模型，为一系列火箭运动模拟增强的极光强迫对黎明和黄昏扇区漫射极光区域的影响。该模型将用于确定在黎明和黄昏漫射极光中产生观测结构的机制、黄昏响应与黎明响应的不同方式和原因、行星际磁场(IMF)的变化对风的大小和结构的影响，以及对太阳和地磁活动以及潮汐强迫条件变化的敏感性。研究人员还将确定E区热层对与膨胀相极光涌动有关的强降水的动力、热力和成分响应，以及热层对最近观测到的大型磁暴的响应，这些磁暴表现出与亚暴的影响不一致的特征。研究结果将向科学界提供，其中将包括E区热层的风、成分和温度对与磁暴和亚暴有关的不同太阳和地磁活动、基金组织取向和潮汐强迫的极光强迫增强的反应的系统细节。该模型还将用于合作研究项目以及涉及研究生和本科生的研究和教学研究。

The investigators will study the response of the E region neutral thermosphere to enhanced auroral forcing. In particular, the aim is to explain and understand phenomena observed within the dawn and dusk recovery phase diffuse aurora, and the thermospheric response to expansion phase surges and new phenomena observed during large magnetic storms. These topics involve areas that are of importance to the space physics and aeronomy community where knowledge is limited. Previous work entailed the simulation of thermospheric response to the dawn sector diffuse aurora using a 3-dimensional (3-D), high resolution, non-hydrostatic, composition-dependent model. The model was able to reproduce the very strong shears in the region of the dawn sector diffuse aurora and unstable regions below the shears, within the same altitude range as those found in the ARIA (Atmospheric Response in Aurora) rocket measurements. The results of the previous research project suggested that propagating tidal modes play an important role in producing the observed structure, in addition to geomagnetic forcing. In this study, the investigators will model the effects of enhanced auroral forcing on the region of the dawn and dusk sector diffuse aurora, for a series of rocket campaigns, using the 3-D high resolution model. The model will be used to determine the mechanisms responsible for producing the observed structures in both the dawn and dusk diffuse aurora, how and why the dusk response differs from the dawn response, the effects of changes in the interplanetary magnetic field (IMF) on wind magnitudes and structures, and the sensitivity to changes in conditions of solar and geomagnetic activity and tidal forcing. The investigators will also determine the dynamical, thermal, and compositional response of the E region thermosphere to the intense precipitation associated with expansion phase auroral surges, as well as the thermospheric response to recently observed large magnetic storms which show characteristics inconsistent with the effects of substorms. The results of the research will be made available to the scientific community, and will include systematic details of the response of the winds, composition and temperature in the E region thermosphere to the enhanced auroral forcing associated with magnetic storms and substorms for varying solar and geomagnetic activity, IMF orientation, and tidal forcing. The model will also be made available for use in collaborative research projects and for research and teaching studies involving graduate and undergraduate students.