First observation of rising-tone magnetosonic waves

0438269 - ÚFA 2015 RIV US eng J - Journal Article
Fu, H. S. - Cao, J. B. - Zhima, Z. - Khotyaintsev, Y. V. - Angelopoulos, V. - Santolík, Ondřej - Omura, Y. - Taubenschuss, U. - Chen, L. - Huang, S. Y.
First observation of rising-tone magnetosonic waves.
Geophysical Research Letters. Roč. 41, č. 21 (2014), s. 7419-7426. ISSN 0094-8276. E-ISSN 1944-8007
R&D Projects: GA MŠMT 7E12026; GA MŠMT(CZ) LH11122
Institutional support: RVO:68378289
Keywords : equatorial noise * ring distributions * cluster * propagation * emissions * region * themis * chorus
Subject RIV: DG - Athmosphere Sciences, Meteorology
Impact factor: 4.196, year: 2014
http://onlinelibrary.wiley.com/doi/10.1002/2014GL061867/abstract

Magnetosonic (MS) waves are linearly polarized emissions confined near the magnetic equator with wave normal angle near 90 degrees and frequency below the lower hybrid frequency. Such waves, also termed equatorial noise, were traditionally known to be "temporally continuous" in their time-frequency spectrogram. Here we show for the first time that MS waves actually have discrete wave elements with rising-tone features in their spectrogram. The frequency sweep rate of MS waves, similar to 1 Hz/s, is between that of chorus and electromagnetic ion cyclotron (EMIC) waves. For the two events we analyzed, MS waves occur outside the plasmapause and cannot penetrate into the plasmasphere; their power is smaller than that of chorus. We suggest that the rising-tone feature of MS waves is a consequence of nonlinear wave-particle interaction, as is the case with chorus and EMIC waves.
Permanent Link: http://hdl.handle.net/11104/0241714