Low frequency nonlinear waves in the auroral plasma

Abstract

The nonlinear evolution of low frequency electrostatic waves in a magnetised plasma is investigated for parameters characteristic of the auroral acceleration region. Our model consists of Boltzmann electrons and warm ions. Using fluid theory, a nonlinear evolution equation is derived for the wave potential. Numerical solutions show the existence of sinusoidal, sawtooth or bipolar waveforms. The effects of plasma parameters on the wave amplitude are examined, in particular the effect of a finite ion temperature.