Langmuir Turbulence in the Auroral Ionosphere: Origins and Effects
Autor: | David L. Newman, James W. LaBelle, Hassanali Akbari |
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Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
Langmuir
010504 meteorology & atmospheric sciences Langmuir Turbulence lcsh:Astronomy beam-plasma interactions Incoherent scatter radar echoes Electron Plasma oscillation 01 natural sciences law.invention plasma waves lcsh:QB1-991 law Dispersion relation 0103 physical sciences Radar 010303 astronomy & astrophysics 0105 earth and related environmental sciences Physics lcsh:QC801-809 Astronomy and Astrophysics Langmuir turbulence Computational physics lcsh:Geophysics. Cosmic physics Physics::Space Physics auroral ionosphere Ionosphere |
Zdroj: | Frontiers in Astronomy and Space Sciences, Vol 7 (2021) |
Popis: | Theory and observations of Langmuir waves and turbulence induced in the auroral ionosphere by electron beams of magnetospheric-origin are reviewed. The theoretical discussions include a brief description of the electrostatic dispersion relation, excitation of Langmuir waves by electron beams, and the stability of beam distributions. The theory of Langmuir turbulence—including the parametric decay instability and wave collapse—is also briefly discussed. The main focus of the review, however, is on the observations of Langmuir waves and turbulence in the ionosphere by in-situ and ground-based sensors. A summary of five decades of in-situ wave and particle observations is presented and combined with a collection of more recent results from ground-based instruments. The ground-based observations include signatures of Langmuir turbulence in the form of coherent echoes in incoherent scatter radar measurements; signatures of electron beams in the form of auroral morphologies recorded by high-speed, high-resolution optical imagers; and electromagnetic emissions received on the ground at high latitudes. Uniting the various observations obtained by the vastly different sensors is shown to provide further insight into the micro-scale processes that occur in the ionosphere. Also discussed in this review is the potential of the ground-based sensors to provide a broader spatial and temporal context for single-point in-situ measurements of such processes. |
Databáze: | OpenAIRE |
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