Articles | Volume 29, issue 11
Ann. Geophys., 29, 1997–2001, 2011

Special issue: Dynamical processes in space plasmas

Ann. Geophys., 29, 1997–2001, 2011

Regular paper 04 Nov 2011

Regular paper | 04 Nov 2011

Quasi-linear dynamics of Weibel instability

O. A. Pokhotelov1 and O. A. Amariutei2 O. A. Pokhotelov and O. A. Amariutei
  • 1Automatic Control and Systems Engineering, University of Sheffield, Sheffield, UK
  • 2Finnish Meteorological Institute, Geophysical Research Division P.O. Box 503 00101 Helsinki, Finland

Abstract. The quasi-linear dynamics of resonant Weibel mode is discussed. It is found that nonlinear saturation of Weibel mode is accompanied by substantial modification of the distribution function in resonant region. With the growth of the wave amplitude the parabolic bell-like form of the electron distribution function in this region converts into flatter shape, such as parabola of the fourth order. This results in significant weakening of the resonant interaction of the wave with particles. The latter becomes weaker and then becomes adiabatic interaction with the bulk of the plasma. This is similar to the case of Bernstein-Greene-Kruskal (Bernstein et al., 1957) electrostatic waves. The mathematical similarity of the Weibel and magnetic mirror instabilities is discussed.