The E × B instability in auroral arcs

摘要: The E × B instability is predicted to occur in auroral arcs, where it generates oscillations which propagate the direction with speeds of several hundred meters per second, and have wavelengths about 1 km. may cause an otherwise quiescent plasma, or growth fluctuations occurring source ionization. dispersion relation derived under conditions corresponding oval, including effects ion-electron recombination vertical variation collision frequencies. occurs when horizontal gradient logarithm electron density exceeds a value 0.5 10−4 m−1, so that arcs width less than 20 km should exhibit instability. only on one side arc (the electric potential high) we predict asymmetry be produced distribution plasma center narrow arcs.