Micrometeoroid Mass Flux Influences on Space Weather and Middle Atmosphere Aeronomy Studied Using the Six NSF Radars and Modeling

研究人员将对中间层和低热层(MLT)中与流星体有关的过程进行观测和理论研究。这项研究将利用对六个NSF雷达(和相关激光雷达)的观测，因为需要不同的频率、相对于地磁场的视角和纬度/季节来确定整个地球流星体的质量通量，探索头/尾-回波散射机制，并揭示流星体与大气相互作用的细节，包括碎片、烧蚀、溅射以及由此产生的等离子体物理和空气学效应。流星体质量流向中层和低热层(MLT)对该区域的大气学和电动力学的复杂作用，例如以零星E、零星金属层和极地中层夏季回波为代表，仍然是空间天气的一个虚幻的、甚至是未被认识的组成部分。要正确解释流星体周围的等离子体--然后形成流星尾迹--是如何产生和演化的，因此需要对雷达头/尾迹雷达散射过程的无线电科学有详细的了解，从而揭示对溅射、碎片和终端过程的重要见解。这些过程的细节仍然是一个争议的来源。研究人员还将研究流星体金属如何到达潮汐离子、零星E层、夜光云和PMSE。现代高功率、大口径雷达流星观测极大地促进了整个流星物理和相关大气学领域的发展。对雷达流星头/尾迹-回波散射过程的观测和建模/模拟研究提供了有关流星体与大气相互作用的独特见解，也有助于了解流星离子和“烟雾”对电离层D区和E区的贡献。这些观测将提供有关流星体等离子体痕迹如何演变为地磁场排列的等离子体结构的细节，并将探索产生非热雷达散射的令人惊讶和有指导意义的流星体耀斑等离子体波。结合雷达观测，瑞利和金属激光雷达的结果为流星体通量大气研究提供了一个新的维度。进入MLT的流星体流量与太阳系和局部星系过程有关。这些都是“系统的系统”空间天气问题，其中流星体能量耗散加热高层大气与焦耳和极光区的粒子加热处于同一量级--这显然是流星体流量的一个未被认识的特性。这项研究还将导致开发新的雷达成像技术，并帮助解决诸如流星体质量通量在云形成和平流层化学等许多低层大气过程中的作用等问题。探索与流星有关的电动力学和非平衡等离子体物理可能会刺激其他领域的研究，例如电离层加热界。这项研究将涉及研究生和本科生研究人员，以发现和学习交流关于流星体过程、相关的空间气象和系统问题以及相关的大气学的知识为特色。

The investigators will conduct observational and theoretical studies of meteoroid-related processes in the mesosphere and lower thermosphere (MLT). The study will utilize observations at the six NSF radars (and associated lidars), as a diversity of frequencies, viewing angles relative to the geomagnetic field, and latitudes/seasons is required to determine the whole earth meteoroid mass flux, explore the head/trail-echo scattering mechanisms, and to reveal details of the meteoroid interaction with the atmosphere including fragmentation, ablation, sputtering, and the resultant plasma physics and aeronomic effects. The complex role of the meteoroid mass flux to the Mesosphere & Lower-Thermosphere (MLT) on the aeronomy and electrodynamics of this region as represented by, e.g., sporadic-E, sporadic metal layers, and Polar Mesospheric Summer Echoes (PMSE), remains an illusive and even unrecognized component of space weather. Detailed understanding of the radio science of the radar head/trail-echo radar scattering processes is required to correctly interpret how the plasma surrounding the meteoroid--and that then forms the meteor trail--is generated and evolves, thus revealing important insights into sputtering, fragmentation, and terminal processes. Details of these processes remain a source of controversy. The investigators will also study how the meteoroid metals arrive in tidal ion, sporadic-E layers, noctilucent clouds, and PMSE. Modern high-power, large-aperture (HPLA) radar meteor observations have greatly stimulated the entire field of meteor physics and associated aeronomy. Observational and modeling/simulation studies of the radar meteor head/trail-echo scattering processes provide unique insight into meteoroid interaction with the atmosphere and also into the contribution of meteoric ions and "smoke" to the ionospheric D- and E-regions. The observations will provide details on how the meteoroid plasma trail evolves into geomagnetic field aligned plasma structures and will explore the surprising and instructive meteoroid flare generated plasma waves that produce non-thermal radar scattering. Together with radar observations, Rayleigh and metal lidar results provide a new dimension to meteoroid flux aeronomic studies. The meteoroid flux into the MLT is linked to solar system and local galactic processes. These are "systems of systems" space weather issues where meteoroid energy dissipation heating of the upper atmosphere is of the same order as Joule and particle heating of the auroral zones--an apparently unrecognized property of the meteoroid flux. This study will also lead to the development of new radar imaging techniques and help address issues such as the role of the meteoroid mass flux in many lower atmospheric processes such as cloud formation and stratospheric chemistry. Exploration of meteor-related electrodynamics and non-equilibrium plasma physics may stimulate other areas of research in, for example, the ionospheric heating community. This research will involve both graduate and undergraduate researchers, featuring discovery and learning to communicate knowledge concerning the meteoroid processes, related spaceweather and systems issues, and associated aeronomy.