Evidence for the interplanetary electric potential? WIND observations of electrostatic fluctuations
In the solar wind at 1 AU, coherent electrostatic waveforms in the ion acoustic frequency range (<u>~</u> 1 kHz) have been observed by the Time Domain Sampler (TDS) instrument on the Wind spacecraft. Small drops of electrostatic potential (<font face="Symbol">D</...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2002-05-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/20/609/2002/angeo-20-609-2002.pdf |
| _version_ | 1818108686478868480 |
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| author | C. Lacombe C. Lacombe C. Lacombe C. Salem A. Mangeney D. Hubert C. Perche J.-L. Bougeret P. J. Kellogg J.-M. Bosqued |
| author_facet | C. Lacombe C. Lacombe C. Lacombe C. Salem A. Mangeney D. Hubert C. Perche J.-L. Bougeret P. J. Kellogg J.-M. Bosqued |
| author_sort | C. Lacombe |
| collection | DOAJ |
| description | In the solar wind at 1
AU, coherent electrostatic waveforms in the ion acoustic frequency range (<u>~</u>
1 kHz) have been observed by the Time Domain Sampler (TDS) instrument on the
Wind spacecraft. Small drops of electrostatic potential (<font face="Symbol">D</font>f
<u>></u> 10<sup>-3</sup> V) have been found across some of these
waveforms, which can thus be considered as weak double layers (Mangeney et al.,
1999). The rate of occurrence of these potential drops, at 1 AU, is estimated
by a comparison of the TDS data with simultaneous data of another Wind
instrument, the Thermal Noise Receiver (TNR), which measures continuously the
thermal and non-thermal electric spectra above 4 kHz. We assume that the
potential drops have a constant amplitude and a constant rate of occurrence
between the Sun and the Earth. The total potential drop between the Sun and the
Earth, which results from a succession of small potential drops during the
Sun-Earth travel time, is then found to be about 300 V to 1000 V, of the same
order of magnitude as the interplanetary potential implied by a two-fluid or an
exospheric model of the solar wind: the interplanetary potential may manifest
itself as a succession of weak double layers. We also find that the hourly
average of the energy of the non-thermal ion acoustic waves, observed on TNR
between 4 and 6 kHz, is correlated to the interplanetary electrostatic field,
parallel to the spiral magnetic field, calculated with a two-fluid model: this
is another evidence of a relation between the interplanetary electrostatic
field and the electrostatic fluctuations in the ion acoustic range. We have yet
to discuss the role of the Doppler effect, which is strong for ion acoustic
waves in the solar wind, and which can bias the measure of the ion acoustic
wave energy in the narrow band 4–6 kHz.<br><br><b>Key words. </b>Interplanetary physics
(plasma waves and turbulence; solar wind plasma) Space plasma physics
(electro-static structures) |
| first_indexed | 2024-12-11T02:19:18Z |
| format | Article |
| id | doaj.art-f800fc104c2d45c086b3e5f7345a8c21 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-11T02:19:18Z |
| publishDate | 2002-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-f800fc104c2d45c086b3e5f7345a8c212022-12-22T01:24:06ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762002-05-012060961810.5194/angeo-20-609-2002Evidence for the interplanetary electric potential? WIND observations of electrostatic fluctuationsC. Lacombe0C. Lacombe1C. Lacombe2C. Salem3A. Mangeney4D. Hubert5C. Perche6J.-L. Bougeret7P. J. Kellogg8J.-M. Bosqued9DESPA/CNRS, Observatoire de Paris, 92195 Meudon, FranceCorrespondence to: C. Lacombe(clacombe@despace.obspm.fr)Space Science Laboratory, University of California, Berkeley, CA 94720, USADESPA/CNRS, Observatoire de Paris, 92195 Meudon, FranceDESPA/CNRS, Observatoire de Paris, 92195 Meudon, FranceDESPA/CNRS, Observatoire de Paris, 92195 Meudon, FranceDESPA/CNRS, Observatoire de Paris, 92195 Meudon, FranceSchool of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55454, USACESR/CNRS, Université Paul Sabatier, BP 4346, 31029 Toulouse, FranceIn the solar wind at 1 AU, coherent electrostatic waveforms in the ion acoustic frequency range (<u>~</u> 1 kHz) have been observed by the Time Domain Sampler (TDS) instrument on the Wind spacecraft. Small drops of electrostatic potential (<font face="Symbol">D</font>f <u>></u> 10<sup>-3</sup> V) have been found across some of these waveforms, which can thus be considered as weak double layers (Mangeney et al., 1999). The rate of occurrence of these potential drops, at 1 AU, is estimated by a comparison of the TDS data with simultaneous data of another Wind instrument, the Thermal Noise Receiver (TNR), which measures continuously the thermal and non-thermal electric spectra above 4 kHz. We assume that the potential drops have a constant amplitude and a constant rate of occurrence between the Sun and the Earth. The total potential drop between the Sun and the Earth, which results from a succession of small potential drops during the Sun-Earth travel time, is then found to be about 300 V to 1000 V, of the same order of magnitude as the interplanetary potential implied by a two-fluid or an exospheric model of the solar wind: the interplanetary potential may manifest itself as a succession of weak double layers. We also find that the hourly average of the energy of the non-thermal ion acoustic waves, observed on TNR between 4 and 6 kHz, is correlated to the interplanetary electrostatic field, parallel to the spiral magnetic field, calculated with a two-fluid model: this is another evidence of a relation between the interplanetary electrostatic field and the electrostatic fluctuations in the ion acoustic range. We have yet to discuss the role of the Doppler effect, which is strong for ion acoustic waves in the solar wind, and which can bias the measure of the ion acoustic wave energy in the narrow band 4–6 kHz.<br><br><b>Key words. </b>Interplanetary physics (plasma waves and turbulence; solar wind plasma) Space plasma physics (electro-static structures)https://www.ann-geophys.net/20/609/2002/angeo-20-609-2002.pdf |
| spellingShingle | C. Lacombe C. Lacombe C. Lacombe C. Salem A. Mangeney D. Hubert C. Perche J.-L. Bougeret P. J. Kellogg J.-M. Bosqued Evidence for the interplanetary electric potential? WIND observations of electrostatic fluctuations Annales Geophysicae |
| title | Evidence for the interplanetary electric potential? WIND observations of electrostatic fluctuations |
| title_full | Evidence for the interplanetary electric potential? WIND observations of electrostatic fluctuations |
| title_fullStr | Evidence for the interplanetary electric potential? WIND observations of electrostatic fluctuations |
| title_full_unstemmed | Evidence for the interplanetary electric potential? WIND observations of electrostatic fluctuations |
| title_short | Evidence for the interplanetary electric potential? WIND observations of electrostatic fluctuations |
| title_sort | evidence for the interplanetary electric potential wind observations of electrostatic fluctuations |
| url | https://www.ann-geophys.net/20/609/2002/angeo-20-609-2002.pdf |
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