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Chorus, ECH, and Z mode emissions observed at Jupiter and Saturn and possible electron acceleration

Menietti J. D., Y. Y. Shprits, R. B. Horne, E. E. Woodfield, G. B. Hospodarsky, D. A. Gurnett, (2012), Chorus, ECH, and Z mode emissions observed at Jupiter and Saturn and possible electron acceleration, J. of Geophys. Res. [Space Physics], 117, doi:10.1029/2012JA018187

Abstract

In this paper we compare and contrast chorus, electron cyclotron harmonics (ECH), and Z mode emissions observed at Jupiter and Saturn and relate them to recent work on electron acceleration at Earth. Intense chorus emissions are observed near the magnetic equator, the likely source region, but the strongest intensities are on either side of the magnetic equator. Chorus intensities at Jupiter are generally about an order of magnitude larger than at Saturn, and the bandwidth of chorus at Jupiter can reach 7 or 8 kHz (∼0.6 fc), while at Saturn it is typically 2 kHz (∼0.6 fc, also). No higher-latitude information is available at Jupiter; however, high inclination orbits at Saturn by Cassini reveal strong chorus intensities at latitudes extending to over 30°. At Jupiter, initial studies reveal the chorus intensities are sufficient to accelerate electrons by a stochastic process; however, the high density levels near the source region of chorus at Saturn indicate a less efficient process except for local regions such as within plasma injection regions. The role of Z mode in electron acceleration and the role of ECH waves in pitch angle scattering at both Jupiter and Saturn require further study.

Authors (sorted by name)

Gurnett Horne Hospodarsky Menietti Shprits Woodfield

Journal / Conference

Journal Of Geophysical Research (Space Physics)

Acknowledgments

We wish to thank J. Barnholdt for administrative assistance and J. Chrisinger for help with several plots. J.D.M. acknowledges support from JPL contract 1415150 and NASA grant NNX11AM36G. Y.Y.S. wishes to cite support from NASA grants NNX09AF51G and NNX10AK99G. R.B.H. and E.E.W. were supported by STFC grant ST/I001727/1 and NERC.

Grants

1415150 NNX09AF51G NNX10AK99G NNX11AM36G ST/I001727/1

Bibtex

@article{doi:10.1029/2012JA018187,
author = {Menietti, J. D. and Shprits, Y. Y. and Horne, R. B. and Woodfield, E. E. and Hospodarsky, G. B. and Gurnett, D. A.},
year = {2012},
title = {Chorus, ECH, and Z mode emissions observed at Jupiter and Saturn and possible electron acceleration},
journal = {Journal of Geophysical Research: Space Physics},
volume = {117},
number = {A12},
pages = {},
keywords = {-, Electron Acceleration},
doi = {10.1029/2012JA018187},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2012JA018187},
eprint = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2012JA018187},
abstract = {In this paper we compare and contrast chorus, electron cyclotron harmonics (ECH), and Z mode emissions observed at Jupiter and Saturn and relate them to recent work on electron acceleration at Earth. Intense chorus emissions are observed near the magnetic equator, the likely source region, but the strongest intensities are on either side of the magnetic equator. Chorus intensities at Jupiter are generally about an order of magnitude larger than at Saturn, and the bandwidth of chorus at Jupiter can reach 7 or 8 kHz (∼0.6 fc), while at Saturn it is typically 2 kHz (∼0.6 fc, also). No higher-latitude information is available at Jupiter; however, high inclination orbits at Saturn by Cassini reveal strong chorus intensities at latitudes extending to over 30°. At Jupiter, initial studies reveal the chorus intensities are sufficient to accelerate electrons by a stochastic process; however, the high density levels near the source region of chorus at Saturn indicate a less efficient process except for local regions such as within plasma injection regions. The role of Z mode in electron acceleration and the role of ECH waves in pitch angle scattering at both Jupiter and Saturn require further study.}
}