Accession Number : ADA114984

Title :   Nonlinear Evolution of Convecting Plasma Enhancements in the Auroral Ionosphere II. Small Scale Irregularities.

Descriptive Note : Memorandum rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Keskinen,M J ; Ossakow,S L

PDF Url : ADA114984

Report Date : 18 May 1982

Pagination or Media Count : 33

Abstract : The linear stability and nonlinear evolution of small scale density irregularities in local unstable regions of large scale convecting auroral plasma enhancements have been studied using analytical and numerical simulation techniques. Our results show that these small scale size irregularities are driven unstable primarily by the effects of convection and field aligned currents. Furthermore, we find that the density irregularities, in the nonlinear regime, in a plane nearly perpendicular to the magnetic field, resemble steepened striation-like structures (elongated in the north-south direction for equatorward convection) which can form and cascade from kilometer to tens of meter scale sizes on the order of an hour.

Descriptors :   *Plasmas(Physics), *Convection(Atmospheric), *Ionosphere, Nonlinear systems, Aurorae, Evolution(General), Gradients, Drift, Stability, Linearity, Atmospheric density, Mathematical models, Equations of motion, Sizes(Dimensions), Scale, Magnetic fields

Subject Categories : Atmospheric Physics
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE