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

1973年至1988年，在美国国家科学基金会的赞助下，在南极洲进行了简单发射机实验，为科学研究人员提供了前所未有的机会，可以进行控制实验，研究非线性波粒相互作用。南极简易站发射机发射的极低频波会传播到地球吗？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，放大了它们，并产生了新的上升和下降的频率成分。在同一地磁力线的北半球共轭点，用地面无线电接收机观测到修正后的波。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。这些数据被记录下来，后来在空军研究实验室数据保存奖下被数字化。用现代技术分析这些遗留数据集，并将观测结果与最新数值模式进行比较，将有助于解决空间天气研究中的突出问题。哨声模式波是在地球上观测到的频率约为100hz - 30khz的电磁波。它们是影响地球辐射带高能电子数量的主要因素之一。尽管经过几十年的积极研究，关于辐射带中哨声波与高能电子相互作用的重要问题仍未得到解答，这使我们无法可靠地预测辐射带中高能电子通量的强度。高能粒子的这些通量可能对地球静止轨道和低轨道上的航天器、空间站上的宇航员以及天基科学、军事和通信卫星产生重大影响。该项目将研究先前从简单发射机实验中积累的数据收集。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，重点是波的增长和新触发辐射的产生。这些数据分析将指导波粒相互作用的高级数值模拟，以便了解所涉及的基本物理过程，例如产生自然发生的等离子体波，称为“合唱”和“嘶嘶”，以及电磁离子回旋波。该研究项目将通过两所学术机构之间的紧密合作，加强研究和教育的基础设施，并有助于培养研究生和本科生。

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.