Articles | Volume 36, issue 5
ANGEO Communicates
18 Sep 2018
ANGEO Communicates |  | 18 Sep 2018

An excitation mechanism for discrete chorus elements in the magnetosphere

Peter Bespalov and Olga Savina

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Subject: Magnetosphere & space plasma physics | Keywords: Waves and instabilities
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Cited articles

Akhiezer, A. I., Akhiezer, I. A., Polovin, R. V., Sitenko, A. G., and Stepanov, K. N.: Plasma electrodynamics. V.1. Linear theory, Pergamon Press, Oxford, UK, New York, USA, 432 pp., 1975. 
Bell, T. F., Inan, U. S., Haque, N., and Pickett, J. S.: Source regions of banded chorus, Geophys. Res. Lett., 36, L11101,, 2009. 
Bespalov, P. A. and Trakhtengerts, V. Yu.: Cyclotron instability of the Earth radiation belts, Reviews of Plasma Physics, Consultants Bureau, New York, USA, 10, 155–292, 1986. 
Burtis, W. J. and Helliwell, R. A.: Banded chorus? A new type of VLF radiation observed in the magnetosphere by OGO 1 and OGO 3, J. Geophys. Res., 74, 3002–3010,, 1969. 
Burton, R. K. and Holzer, R. E.: The origin and propagation of chorus in the outer magnetosphere, J. Geophys. Res., 79, 1014–1023,, 1974. 
Short summary
A VLF chorus is a very intense electromagnetic plasma wave that is naturally excited as a succession of discrete emissions near the magnetic equatorial plane outside the plasmasphere. We introduce a mechanism of chorus excitation under conditions when known mechanisms become ineffective. This kind of excitation is related to the amplification of short electromagnetic pulses from the noise level even in a stable plasma. Obtained results can explain some important features of the chorus emissions.