High Altitude Limit of the Gradient Drift Instability
Abstract
The gradient drift instability for F region plasma clouds is investigated retaining ion inertia effects. Using the assumption that the ion gyrofrequency, Omega, is greater than inertial time changes (delta/delta T and divergence of V sub I) and the ion-neutral collision frequency, V sub in, a quadratic dispersion equation results. In the limit that V sub in >> 4cE sub O/ BL (E sub O and B are the ambient electric and magnetic fields, and L is the plasma cloud density gradient scale length), the growth rate, gamma, reduces to the usual result CE sub O/BL. In the opposite limit v sub in << 4cE sub O/BL, gamma = (CE sub O V sub in/BL) to the 1/2 power. This result can explain why high altitude (approximately 450 km) Barium releases, where v sub in is less than unity and a factor of 10-100 smaller than at lower altitudes (Approximately 200 km), striate on time scales similar to the lower altitude releases.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1977
- Accession Number
- ADA049503
Entities
People
- J. B. Workman
- P. K. Chaturvedi
- Sidney L. Ossakow
Organizations
- United States Naval Research Laboratory