Collaborative Research: Dayside Field-Aligned Current (FAC) Source Regions of Extreme Poynting Flux Events and the Response of the Magnetosphere-Ionosphere-Thermosphere System

对磁层的大多数研究主要考虑行星际磁场（IMF）的南北分量，其中大多数研究考虑的间隔是向南的IMF （Bz0）。最近的发现揭示了异常的热层中性密度特征，这是由于在通常被认为是良性的条件下，坡印亭通量在非常局部的区域上的强烈沉积造成的。这些研究表明，在风暴开始时，相对温和的由IMF驱动的局部加热产生了中性的热层扰动，这在以前没有得到解释。此外，利用DMSP卫星数据进行的研究表明，白天侧的能量输入很大，但只限于局部。MHD模拟结果表明，南半球局部增强的坡印亭通量映射到一个侧翼磁层顶重联区。这些事件大多与黄道内占主导地位的行星际磁场（IMF）值有关，而IMF Bz是向北的（Bz0）。本研究的目的是验证坡印廷通量相关日侧场向电流（FACs）的源区（磁层顶合并与弓形激波），确定其电离层分布，并研究坡印廷通量能量输入对磁层-电离层-热层系统的相对局部和全球影响。将区分和研究太阳抛射物和高速流的季节和半球差异的影响。这项研究将利用来自多颗卫星的数据分析、来自雷达的地面观测和AMIE技术，并将所有观测结果与全球磁流体动力学模拟结合起来。这项研究有可能改变空间科学界看待非南向IMF对地球空间环境影响的方式。它处于系统科学的最前沿，探索非南向IMF对向白天区域提供集中能量的场对齐电流的影响。这是空间物理学中一个研究不足的领域。它也有实际应用的问题，有关卫星阻力。

Most studies of the magnetosphere have been carried out by considering primarily the north-south (Bz) component of the interplanetary magnetic field (IMF) and most of those have considered intervals with southward IMF (Bz0). Recent discoveries have revealed anomalous thermospheric neutral density signatures caused by intense deposition of Poynting flux delivered over very localized regions under conditions that are normally considered benign. These studies have shown that relatively modest IMF By-driven localized heating at storm-onset generates neutral thermospheric disturbances that had not previously been explained. In addition studies using data from DMSP satellites demonstrated large yet localized dayside energy input. MHD simulation results for one case suggest that the localized enhanced Poynting fluxes in the southern hemisphere map to a flank magnetopause reconnection region. Most of these events are associated with dominant in-the-ecliptic interplanetary magnetic field (IMF) values, often, but not exclusively, while the IMF Bz is northward (Bz0). The objectives of this proposal are to verify the source region (magnetopause merging versus bow shock) of the Poynting flux-related dayside field-aligned currents (FACs), determine their ionospheric distribution, and examine the relative local and global impact of the Poynting flux energy input on the magnetosphere-ionosphere-thermosphere system. The influences of solar ejecta and high-speed streams will be distinguished and investigated for seasonal and hemispheric differences. The study will employ both data analysis from multiple satellites, ground based observations from radar and the AMIE technique and tie all the observations together with global magnetohydrodynamic simulations. This research potentially transforms the way the space science community views the effects of non-southward IMF on the geospace environment. It is at the forefront of system science in exploring the influence of non-southward IMF on the field-aligned currents that deliver focused energy to dayside regions. This is an understudied area of space physics. It also has practical application to problems related to satellite drag.