Ionospheric Turbulence: Interchange Instabilities and Chaotic Fluid Behavior.
Abstract
We develop a set of mode coupling equations which describe the nonlinear evolution of the Rayleigh-Taylor and E X B gradient drift instabilities which are relevant to the ionosphere. The model is restricted to 2D turbulence in the plane transverse to the magnetic field, and only those modes such that kL >> 1 are considered, where k is the wavenumber and L is the scale length of the density gradient. We show that for a three mode system, the nonlinear equations describing these instabilities correspond exactly to the Lorenz equations which approximately describe the Rayleigh-Bernard instability. Following the analysis of Lorenz (1963), it is shown that the three mode system can exhibit a strange attractor with chaotic behavior. Ion inertia plays a critical role in this phenomenon in that if it is neglected (as in the collisional limit), the three mode system does not exhibit chaos and a stable convection pattern results.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 22, 1984
- Accession Number
- ADA147810
Entities
People
- A. B. Hassam
- I. B. Schwartz
- Joseph D. Huba
- Michael J. Keskinen
Organizations
- United States Naval Research Laboratory