Current‐driven Langmuir oscillations and formation of wave packets via modulational instability: Relevance to STEREO observations
Abstract Recently, it has been shown that Langmuir oscillations (LOs) at the plasma frequency can be driven by an electron current without any electrostatic instability. This current may appear due to a (small) drift of the whole electron population against the ions or by beam electrons after their...
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| Format: | Article |
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Wiley
2016-07-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1002/2016GL069872 |
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| author | K. Sauer R. D. Sydora |
| author_facet | K. Sauer R. D. Sydora |
| author_sort | K. Sauer |
| collection | DOAJ |
| description | Abstract Recently, it has been shown that Langmuir oscillations (LOs) at the plasma frequency can be driven by an electron current without any electrostatic instability. This current may appear due to a (small) drift of the whole electron population against the ions or by beam electrons after their relaxation to a plateau‐like distribution. The consequences of LOs for nonlinear wave phenomena in this scenario are studied by means of kinetic plasma simulations. It is shown that the electric field of LOs can act as a pump wave and generate Langmuir envelope solitons via the modulational instability. In this way, both counterstreaming Langmuir and ion‐acoustic waves arise with the same wave number. For solar wind conditions the Doppler shift leads to the generation of satellite peaks with frequencies symmetric around the plasma frequency. Simultaneously, a peak appears in the ion‐acoustic branch. These results agree well with recent STEREO observations in the solar wind. |
| format | Article |
| id | doaj-art-53a77154b5bc42d492700a2235eca6c2 |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2016-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-53a77154b5bc42d492700a2235eca6c22025-08-20T03:10:28ZengWileyGeophysical Research Letters0094-82761944-80072016-07-0143147348735510.1002/2016GL069872Current‐driven Langmuir oscillations and formation of wave packets via modulational instability: Relevance to STEREO observationsK. Sauer0R. D. Sydora1Department of Physics University of Alberta Edmonton Alberta CanadaDepartment of Physics University of Alberta Edmonton Alberta CanadaAbstract Recently, it has been shown that Langmuir oscillations (LOs) at the plasma frequency can be driven by an electron current without any electrostatic instability. This current may appear due to a (small) drift of the whole electron population against the ions or by beam electrons after their relaxation to a plateau‐like distribution. The consequences of LOs for nonlinear wave phenomena in this scenario are studied by means of kinetic plasma simulations. It is shown that the electric field of LOs can act as a pump wave and generate Langmuir envelope solitons via the modulational instability. In this way, both counterstreaming Langmuir and ion‐acoustic waves arise with the same wave number. For solar wind conditions the Doppler shift leads to the generation of satellite peaks with frequencies symmetric around the plasma frequency. Simultaneously, a peak appears in the ion‐acoustic branch. These results agree well with recent STEREO observations in the solar wind.https://doi.org/10.1002/2016GL069872type III radio burstsLangmuir wavesmodulational instabilitysolitonskinetic simulations |
| spellingShingle | K. Sauer R. D. Sydora Current‐driven Langmuir oscillations and formation of wave packets via modulational instability: Relevance to STEREO observations Geophysical Research Letters type III radio bursts Langmuir waves modulational instability solitons kinetic simulations |
| title | Current‐driven Langmuir oscillations and formation of wave packets via modulational instability: Relevance to STEREO observations |
| title_full | Current‐driven Langmuir oscillations and formation of wave packets via modulational instability: Relevance to STEREO observations |
| title_fullStr | Current‐driven Langmuir oscillations and formation of wave packets via modulational instability: Relevance to STEREO observations |
| title_full_unstemmed | Current‐driven Langmuir oscillations and formation of wave packets via modulational instability: Relevance to STEREO observations |
| title_short | Current‐driven Langmuir oscillations and formation of wave packets via modulational instability: Relevance to STEREO observations |
| title_sort | current driven langmuir oscillations and formation of wave packets via modulational instability relevance to stereo observations |
| topic | type III radio bursts Langmuir waves modulational instability solitons kinetic simulations |
| url | https://doi.org/10.1002/2016GL069872 |
| work_keys_str_mv | AT ksauer currentdrivenlangmuiroscillationsandformationofwavepacketsviamodulationalinstabilityrelevancetostereoobservations AT rdsydora currentdrivenlangmuiroscillationsandformationofwavepacketsviamodulationalinstabilityrelevancetostereoobservations |