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Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Source region and growth analysis of narrowband Z-mode emission at Saturn
AU - Menietti, J. D.
AU - Yoon, P. H.
AU - Pisa, D.
AU - Ye, S.-Y.
AU - Santolik, O.
AU - Arridge, Christopher Stephen
AU - Gurnett, D.A.
AU - Coates, A. J.
N1 - ©2016. American Geophysical Union. All Rights Reserved.
PY - 2016/12
Y1 - 2016/12
N2 - Intense Z-mode emission is observed in the lower density region near the inner edge of the Enceladus torus at Saturn, where these waves may resonate with MeV electrons. The source mechanism of this emission, which is narrow-banded and most intense near 5 kHz, is not well understood. We survey the Cassini Radio and Plasma Wave Science data to isolate several probable source regions near the inner edge of the Enceladus density torus. Electron phase space distributions are obtained from the Cassini Electron Spectrometer, part of the Cassini Plasma Spectrometer investigation. We perform a plasma wave growth analysis to conclude that an electron temperature anisotropy and possibly a weak loss cone can drive the Z mode as observed. Electrostatic electron acoustic waves and perhaps weak beam modes are also found to be unstable coincident with the Z mode. Quasi-steady conditions near the Enceladus density torus may result in the observations of narrowband Z-mode emission at Saturn.
AB - Intense Z-mode emission is observed in the lower density region near the inner edge of the Enceladus torus at Saturn, where these waves may resonate with MeV electrons. The source mechanism of this emission, which is narrow-banded and most intense near 5 kHz, is not well understood. We survey the Cassini Radio and Plasma Wave Science data to isolate several probable source regions near the inner edge of the Enceladus density torus. Electron phase space distributions are obtained from the Cassini Electron Spectrometer, part of the Cassini Plasma Spectrometer investigation. We perform a plasma wave growth analysis to conclude that an electron temperature anisotropy and possibly a weak loss cone can drive the Z mode as observed. Electrostatic electron acoustic waves and perhaps weak beam modes are also found to be unstable coincident with the Z mode. Quasi-steady conditions near the Enceladus density torus may result in the observations of narrowband Z-mode emission at Saturn.
KW - wave-particle interactions
KW - planetary magnetospheres
U2 - 10.1002/2016JA022913
DO - 10.1002/2016JA022913
M3 - Journal article
VL - 121
SP - 11929
EP - 11942
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
SN - 2169-9402
IS - 12
ER -