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Summer school - Chalkidiki September 23-28 2003
Transverse instability of Alfven wave
Cluster observations and heuristic explication.
Olga Alexandrova LESIA, Observatoire de Paris,
France.
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Temperature Anisotropy with respect to B is a
source of the waves.
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Observations (multi-satellite Cluster)
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Magnetic field waveforms around the shock
crossing in NML-frame
Time origin is the shock crossing time 180217 UT
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(I) AIC waves (alpha, p)
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region (II)
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Anisotropy relaxation
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Conclusions

• 1) The finite amplitude Alfven wave and the
  resulting filaments are observed downstream of
  the bow shock the possible interpretation is
  Filamentation Instability.
• 2) Filamentation instability seems to play a role
  in the final thermalization.
• 3) Thanks to the 4 satellites of Cluster,
  parameters and behaviour of the observed
  structures are obtained, that gives a possibility
  to compare the observations with the theory.