Heating of heavy ions on auroral field lines in the presence of a large‐amplitude hydrogen cyclotron wave

Abstract

Heating of heavy ions is studied analytically and by means of numerical simulations in the presence of a large‐amplitude hydrogen cyclotron wave which is commonly observed on auroral field lines. Both one‐ and two‐dimensional numerical simulations showed a decay instability resulting in strong heating of both the oxygen ions and the hydrogen ions. In particular, detailed results of simulations in two dimensions where E × B drift plays an important role indicate a much stronger heating of the oxygen ions than that in the one‐dimensional simulation. A high‐energy tail of the oxygen ions is commonly observed in the perpendicular distribution.

Heating of Light Ions in the Presence of a Large Amplitude Heavy Ion Cyclotron Wave

“…In section 2 we present a theoretical analysis of both instabilities caused by the electron parallel and perpendicular drift associated with a larger-amplitude EOC wave. We would like to emphasize that, contrary to our earlier works [Nishikawa et al, 1983[Nishikawa et al, , 1985, the decay instability is not possible here, since i Now at Department of Physics and Astronomy, University of Iowa, Iowa City. the frequencies of current-driven EHC and lower hybrid twostream instabilities are much higher than that of EOC waves.…”

Three-wave coupling coefficient in a drifting bi-Maxwellian plasma

“…Here, the initial wave can be locally linearly generated by some free energy source and can also decay locally. Examples are the decay of linearly excited lower-hybrid (LH) waves to LH waves having lower perpendicular phase velocity and low-frequency modes (Retterer, Chang & Jasperse 1986), and the decay of an electrostatic hydrogen cyclotron (EHC) wave to another EHC wave and an oxygen cyclotron mode (Nishikawa, Okuda & Hasegawa 1985). In each case the goal is to create waves that can resonate with a particular ion species and create the heating observed.…”