On the existence of Alfvén waves in the terrestrial foreshock
The terrestrial foreshock is characterised by the existence of large amplitude ultra low frequency waves. The majority of such waves are observed to be left-handed in the spacecraft frame, but are in fact intrinsically right-handed and have been identified as fast-magnetosonic waves. More ra...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2003-07-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/21/1457/2003/angeo-21-1457-2003.pdf |
| Summary: | The terrestrial foreshock
is characterised by the existence of large amplitude ultra low frequency waves.
The majority of such waves are observed to be left-handed in the spacecraft
frame, but are in fact intrinsically right-handed and have been identified as
fast-magnetosonic waves. More rarely observed are waves that are right-handed
in the spacecraft frame. Cluster four spacecraft observations of such waves are
presented and analysed using multi-spacecraft techniques; in particular the
k-filtering/wave telescope technique is used. The waves are found to be
left-handed and propagating sunwards in the plasma rest frame, and are,
therefore, identified as Alfvénic. The convection of the waves anti-sunward in
the solar wind flow causes the observed polarisation to be reversed. Generation
mechanisms are discussed.<br><br><b>Key words. </b>Interplanetary physics (MHD
waves and turbulence; planetary bow shocks) – Space plasma physics (wave
particle interactions) |
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| ISSN: | 0992-7689 1432-0576 |