Effects of Ion Collisions on Quasilinear Heating by the Current-Driven Ion Cyclotron Instability in the High Latitude Ionosphere
Abstract
Using an effective relaxation time model, the effects of ion-ion and ion-neutral collisions on quasilinear ion heating by the current-driven ion cyclotron instability in the high latitude ionosphere have been studied. For conditions typical of the high latitude lower (200-300 km) F-region ionosphere, it is found that the combined effects of ion-neutral and ion-ion collisions tend to isotropize (S(tet)/T(par) approx. 1) the perpendicular T(per) and parallel S(tet) ion temperatures on time scales on the order of several tens to hundreds of NO+ cyclotron periods for wave amplitudes e(phi)/T sub e = 0.2. Here, phi is the wave electrostatic potential, T(par) the electron temperature (in energy units), e is the electron charge. In addition, for the high latitude upper (600 km) F-region ionosphere it is found that stronger anisotropy (T(per)/T(par) > 3) can be sustained even in the presence of ion collisions with waves with amplitudes e(phi)/T sub e = 0.2. For larger amplitude waves e(phi)/T sub e = 0. 4, we find that the heating is weakly anisotropic at low altitudes (200-300 km) and strongly anisotropic at higher (600 km) altitudes. In both wave amplitude regimes (0.2 and 0.4), we find perpendicular ion heating factors about 2-10 for altitudes in the range 300-600km, with the larger perpendicular heating occurring at higher altitudes and larger wave amplitudes. The results are compared with recent rocket and satellite observations in the high latitude ionosphere. Keywords: Ion cyclotron instability; Ion heating.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 14, 1988
- Accession Number
- ADA202512
Entities
People
- Michael J. Keskinen
- P. K. Chaturvedi
- P. Satyanarayana
- Sidney L. Ossakow
Organizations
- United States Naval Research Laboratory