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

使用六台 NSF 雷达和建模研究微流星体质量通量对空间天气和中层大气航空学的影响

• 批准号: 1202019
• 负责人: John Mathews
• 金额: $ 54万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1202019&HistoricalAwards=false
• 关键词: Micrometeoroid; Mass; Flux; Influences; Space

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.

研究人员将对中层和低热层（MLT）中与流星体相关的过程进行观测和理论研究。 该研究将利用六个 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以及纬度/季节来确定整个地球流星体质量通量、探索头部/尾迹-回波散射机制，并揭示流星体与大气相互作用的细节，包括碎裂、烧蚀、溅射以及由此产生的等离子体物理和空气效应。流向中层和低热层 (MLT) 的流星体质量通量对该区域的空气动力学和电动力学的复杂作用仍然存在，如零星 E、零星金属层和极地中层夏季回波 (PMSE) 等。太空天气的一个虚幻的、甚至未被认识的组成部分。 需要详细了解雷达头/尾迹回波雷达散射过程的无线电科学，才能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，从而揭示对溅射的重要见解、碎片和终端进程。 这些过程的细节仍然存在争议。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。 现代高功率大孔径（HPLA）雷达流星观测极大地刺激了流星物理学和相关航空学的整个领域。雷达流星头/尾迹回波散射过程的观测和建模/模拟研究为流星体与大气的相互作用以及流星离子和“烟雾”对电离层 D 区和 E 区的贡献提供了独特的见解。观测结果将提供有关流星体等离子体尾迹如何演化为与地磁场对齐的等离子体结构的详细信息，并将探索令人惊讶且有启发性的流星体耀斑产生的等离子体波，这些等离子体波会产生非热雷达散射。与雷达观测一起，瑞利和金属激光雷达结果为流星体通量航空研究提供了新的维度。进入 MLT 的流星体通量与太阳系和当地银河过程有关。 这些是“系统的系统”空间天气问题，其中高层大气的流星体能量耗散加热与极光区的焦耳和粒子加热处于同一数量级——流星体通量的一个显然未被识别的特性。 这项研究还将促进新雷达成像技术的发展，并有助于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。与流星相关的电动力学和非平衡等离子体物理学的探索可能会刺激其他领域的研究，例如电离层加热领域。 这项研究将涉及研究生和本科生研究人员，其特点是发现和学习交流有关流星体过程、相关空间天气和系统问题以及相关航空学的知识。