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Observations of large‐amplitude, parallel, electrostatic waves associated with the Kelvin‐Helmholtz instability by the magnetospheric multiscale mission
Author(s) -
Wilder F. D.,
Ergun R. E.,
Schwartz S. J.,
Newman D. L.,
Eriksson S.,
Stawarz J. E.,
Goldman M. V.,
Goodrich K. A.,
Gershman D. J.,
Malaspina D. M.,
Holmes J. C.,
Sturner A. P.,
Burch J. L.,
Torbert R. B.,
Lindqvist P.A.,
Marklund G. T.,
Khotyaintsev Y.,
Strangeway R. J.,
Russell C. T.,
Pollock C. J.,
Giles B. L.,
Dorrelli J. C.,
Avanov L. A.,
Patterson W. R.,
Plaschke F.,
Magnes W.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl070404
Subject(s) - physics , magnetopause , amplitude , instability , magnetosheath , geophysics , computational physics , plasma , plasma sheet , electric field , magnetosphere , spacecraft , electron , magnetic field , mechanics , optics , astronomy , quantum mechanics
Abstract On 8 September 2015, the four Magnetospheric Multiscale spacecraft encountered a Kelvin‐Helmholtz unstable magnetopause near the dusk flank. The spacecraft observed periodic compressed current sheets, between which the plasma was turbulent. We present observations of large‐amplitude (up to 100 mV/m) oscillations in the electric field. Because these oscillations are purely parallel to the background magnetic field, electrostatic, and below the ion plasma frequency, they are likely to be ion acoustic‐like waves. These waves are observed in a turbulent plasma where multiple particle populations are intermittently mixed, including cold electrons with energies less than 10 eV. Stability analysis suggests a cold electron component is necessary for wave growth.