Waveform and packet structure of lion roars
The Equator-S magnetometer is very sensitive and has a sampling rate of normally 128 Hz. The high sampling rate allows for the first time fluxgate magnetometer measurements of ELF waves between the ion cyclotron and the lower hybrid frequencies in the equatorial dayside magnetosheath. The so-cal...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
1999-12-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/17/1528/1999/angeo-17-1528-1999.pdf |
| _version_ | 1811314335448825856 |
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| author | W. Baumjohann R. A. Treumann E. Georgescu E. Georgescu G. Haerendel K.-H. Fornacon U. Auster |
| author_facet | W. Baumjohann R. A. Treumann E. Georgescu E. Georgescu G. Haerendel K.-H. Fornacon U. Auster |
| author_sort | W. Baumjohann |
| collection | DOAJ |
| description | The Equator-S magnetometer is very sensitive
and has a sampling rate of normally 128 Hz. The high sampling rate allows for
the first time fluxgate magnetometer measurements of ELF waves between the ion
cyclotron and the lower hybrid frequencies in the equatorial dayside
magnetosheath. The so-called lion roars, typically seen by the Equator-S
magnetometer at the bottom of the magnetic troughs of magnetosheath mirror
waves, are near-monochromatic packets of electron whistler waves lasting for a
few wave cycles only, typically 0.25 s. They are right-hand circularly polarized
waves with typical amplitudes of 0.5–1 nT at around one tenth of the electron
gyrofrequency. The cone angle between wave vector and ambient field is usually
smaller than 1.5<sup>°</sup>.<br><br><b>Key words.</b> Interplanetary physics (MHD waves and
turbulence; plasma waves and turbulence) |
| first_indexed | 2024-04-13T11:10:02Z |
| format | Article |
| id | doaj.art-7ea71110a48e468bb1fe0d76fd7ee6bd |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-13T11:10:02Z |
| publishDate | 1999-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-7ea71110a48e468bb1fe0d76fd7ee6bd2022-12-22T02:49:09ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05761999-12-01171528153410.1007/s00585-999-1528-9Waveform and packet structure of lion roarsW. Baumjohann0R. A. Treumann1E. Georgescu2E. Georgescu3G. Haerendel4K.-H. Fornacon5U. Auster6Max-Planck-Institut für extraterrestrische Physik, Garching, GermanyMax-Planck-Institut für extraterrestrische Physik, Garching, GermanyMax-Planck-Institut für extraterrestrische Physik, Garching, GermanyInstitut for Space Sciences, Bucharest, RomaniaMax-Planck-Institut für extraterrestrische Physik, Garching, GermanyInstitut für Geophysik und Meteorologie, TU Braunschweig, GermanyInstitut für Geophysik und Meteorologie, TU Braunschweig, GermanyThe Equator-S magnetometer is very sensitive and has a sampling rate of normally 128 Hz. The high sampling rate allows for the first time fluxgate magnetometer measurements of ELF waves between the ion cyclotron and the lower hybrid frequencies in the equatorial dayside magnetosheath. The so-called lion roars, typically seen by the Equator-S magnetometer at the bottom of the magnetic troughs of magnetosheath mirror waves, are near-monochromatic packets of electron whistler waves lasting for a few wave cycles only, typically 0.25 s. They are right-hand circularly polarized waves with typical amplitudes of 0.5–1 nT at around one tenth of the electron gyrofrequency. The cone angle between wave vector and ambient field is usually smaller than 1.5<sup>°</sup>.<br><br><b>Key words.</b> Interplanetary physics (MHD waves and turbulence; plasma waves and turbulence)https://www.ann-geophys.net/17/1528/1999/angeo-17-1528-1999.pdf |
| spellingShingle | W. Baumjohann R. A. Treumann E. Georgescu E. Georgescu G. Haerendel K.-H. Fornacon U. Auster Waveform and packet structure of lion roars Annales Geophysicae |
| title | Waveform and packet structure of lion roars |
| title_full | Waveform and packet structure of lion roars |
| title_fullStr | Waveform and packet structure of lion roars |
| title_full_unstemmed | Waveform and packet structure of lion roars |
| title_short | Waveform and packet structure of lion roars |
| title_sort | waveform and packet structure of lion roars |
| url | https://www.ann-geophys.net/17/1528/1999/angeo-17-1528-1999.pdf |
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