Excitation of poloidal standing Alfv�n waves through drift resonance wave-particle interaction

Please use this identifier to cite or link to this item: https://ir.lib.ncu.edu.tw/handle/987654321/104669

Title:	Excitation of poloidal standing Alfv�n waves through drift resonance wave-particle interaction
Authors:	陳騮;Dai, Lei;Takahashi, Kazue;Wygant, John R.;Chen, Liu;Bonnell, John;Cattell, Cynthia A.;Thaller, Scott;Kletzing, Craig;Smith, Charles W.;MacDowall, Robert J.;Baker, Daniel N.;Blake, J. Bernard;Fennell, Joseph;Claudepierre, Seth;Funsten, Herbert O.;Reeves, Geoffrey D.;Spence, Harlan E.
Contributors:	理學院物理學系
Keywords:	Drift;drift resonance;Earth sciences;Earth, ocean, space;Electric fields;Energy sources;Exact sciences and technology;Geophysics;Instability;Magnetic fields;Magnetic resonance;Oscillations;poloidal standing wave;Resonance;ring current;Spacecraft;Spectral analysis;Stability;Wave-particle interactions
Date:	2013-08-28
Issue Date:	2026-04-23 11:55:10 (UTC+8)
Publisher:	Wiley-Blackwell;Washington, DC: Blackwell Publishing Ltd
Abstract:	摘要： Drift‐resonance wave‐particle interaction is a fundamental collisionless plasma process studied extensively in theory. Using cross‐spectral analysis of electric field, magnetic field, and ion flux data from the Van Allen Probe (Radiation Belt Storm Probes) spacecraft, we present direct evidence identifying the generation of a fundamental mode standing poloidal wave through drift‐resonance interactions in the inner magnetosphere. Intense azimuthal electric field (Eφ) oscillations as large as 10mV/m are observed, associated with radial magnetic field (Br) oscillations in the dawn‐noon sector near but south of the magnetic equator at L∼5. The observed wave period, Eφ/Br ratio and the 90° phase lag between Br and Eφ are all consistent with fundamental mode standing Poloidal waves. Phase shifts between particle fluxes and wave electric fields clearly demonstrate a drift resonance with ∼90 keV ring current ions. The estimated earthward gradient of ion phase space density provides a free energy source for wave generation through the drift‐resonance instability. A similar drift‐resonance process should occur ubiquitously in collisionless plasma systems. One specific example is the “fishbone” instability in fusion plasma devices. In addition, our observations have important implications for the long‐standing mysterious origin of Giant Pulsations. 其他題名： Geophys. Res. Lett 出版者： Washington, DC: Blackwell Publishing Ltd 出版日期： 2013-08-28 出處： Geophysical Research Letters, 2013-08, Vol.40 (16), p.4127-4132 資源來源： Wiley Online Library - AutoHoldings Journals 版權： 2013. American Geophysical Union. All Rights Reserved. 版權： 2014 INIST-CNRS 識別號： ISSN: 0094-8276 識別號： EISSN: 1944-8007 識別號： DOI: 10.1002/grl.50800 識別號： CODEN: GPRLAJ
Appears in Collections:	[Department of Physics] journal & Dissertation

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