Collaborative Research: Analysis and Modeling of Nonlinear Wave-Particle Interactions from the Siple Transmitter Experiment

合作研究：单发射机实验中非线性波粒相互作用的分析和建模

• 批准号: 1542608
• 负责人: Mark Golkowski
• 金额: $ 24.29万
• 依托单位: University of Colorado at Denver
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1542608&HistoricalAwards=false
• 关键词: Collaborative; Research; Analysis; Modeling; Nonlinear

The Siple Transmitter Experiment, operated in Antarctica from 1973 to 1988 under sponsorship from the National Science Foundation, provided scientific researchers with a heretofore unmatched opportunity to perform controlled experiments to study nonlinear wave-particle interactions. Very low frequency waves radiated by the transmitter at the Antarctic Siple Station propagated into the Earth?s magnetosphere where they interacted with the energetic electrons in the Radiation Belts. This interaction modified the waves, amplifying them and generating new rising and falling frequency components. The modified waves were observed with radio receivers on the ground at the Northern Hemisphere conjugate points of the same geomagnetic field line. These "triggered" waves bear similarities to naturally occurring "chorus" type waves that are a major driver of space weather processes. The data were recorded and later digitized under the Air Force Research Laboratory data-preservation award. Analyzing this legacy dataset with modern techniques and comparing observations to the latest numerical models will help resolve outstanding issues in space weather research. Whistler-mode waves are the electromagnetic waves with frequency of about 100 Hz-30 kHz, observed in Earth?s magnetosphere, and they are one of the major factors significantly affecting the energetic electrons population in the Earth's Radiation Belts. Despite many decades of active research, important questions on the whistler waves interaction with energetic electrons in the Radiation Belts still remain unanswered, which does not allow us to predict reliably the intensity of energetic electron fluxes in the Radiation Belts. These fluxes of energetic particles may significantly affect spacecraft in the geostationary and low orbits, astronauts in the space station, as well space-based scientific, military, and communication satellites. This project will study previously accumulated collection of data from the Siple Transmitter Experiment. Statistical analysis of these data in combination with numerical simulations will be used to characterize the dynamics of nonlinear interactions of whistler waves with energetic particles, focusing on the wave growth and generation of newly triggered emissions. This data analysis will guide advanced numerical simulations of the wave-particle interactions in order to understand fundamental physical processes involved, such as generation of naturally occurring plasma waves called "chorus" and "hiss" and also electromagnetic ion cyclotron waves. This research project will enhance infrastructure for research and education through a strong collaboration between two academic institutions and contribute to the training of graduate and undergraduate students.

单发射机实验于 1973 年至 1988 年在美国国家科学基金会的资助下在南极洲进行，为科学研究人员提供了前所未有的机会来进行受控实验来研究非线性波粒相互作用。南极单站发射机辐射的极低频波传播到地球磁层，在那里它们与辐射带中的高能电子相互作用。这种相互作用改变了波，将其放大并产生新的上升和下降频率分量。 修改后的波是用地面无线电接收器在同一地磁场线的北半球共轭点观测到的。 这些“触发”波与自然发生的“合唱”型波有相似之处，后者是空间天气过程的主要驱动力。根据空军研究实验室数据保存奖，这些数据被记录并随后数字化。使用现代技术分析这个遗留数据集并将观测结果与最新的数值模型进行比较将有助于解决空间天气研究中的突出问题。 惠斯勒模波是在地球磁层中观测到的频率约为100 Hz-30 kHz的电磁波，是显着影响地球辐射带高能电子数量的主要因素之一。尽管进行了数十年的积极研究，但关于哨声波与辐射带中高能电子相互作用的重要问题仍然没有得到解答，这使得我们无法可靠地预测辐射带中高能电子通量的强度。这些高能粒子通量可能会对地球静止轨道和低轨道上的航天器、空间站中的宇航员以及天基科学、军事和通信卫星产生重大影响。该项目将研究之前从简单发射器实验中收集的数据。这些数据的统计分析与数值模拟相结合，将用于表征哨声波与高能粒子的非线性相互作用的动力学，重点关注波的增长和新触发发射的产生。该数据分析将指导波粒相互作用的高级数值模拟，以了解所涉及的基本物理过程，例如产生称为“合唱”和“嘶嘶声”的自然发生的等离子体波以及电磁离子回旋波。该研究项目将通过两个学术机构之间的强有力合作加强研究和教育基础设施，并有助于研究生和本科生的培训。