Alfvenic solitons in ultrarelativistic electron-positron plasmas.

A

Resonant electromagnetic ion‐ion beam turbulence at comet P/Grigg‐Skjellerup

The electromagnetic turbulence and associated frequencies observed far upstream of comet P/Grigg-Skjellerup during the recent Giotto spacecraft flyby can be attributed to relative streaming between the cometary ions and the solar wind, and the hypothesis that unstable parallel modes are responsible is used to deduce the wavelengths involved. Such a self-consistent approach yields resonant instabilities with wavelengths of 7000 approximately 8000 km, phase velocities which are sub-Alfvenic and polarizations which are left-handed in the spacecraft frame