Plasma Lines in the Auroral E Layer

Conditions for Double Layers in the Earth's Magnetosphere and Perhaps in Other Astrophysical Objects

Double layers (i.e., electric fields parallel to B) form along auroral field lines in the Earth's magnetosphere. They form in order to maintain current continuity in the ionosphere in the presence of a magnetospheric electric field E with V • E 4: 0. Features which govern the formation of the double layers are: (1) the divergence of E, (2) the conductivity of the ionosphere, and (3) the current...

Kinetic Theory of the Alfvén Wave Acceleration of Auroral Electrons

Recent observations have indicated that in addition to the classical “inverted-V” type electron acceleration, auroral electrons often have a field-aligned distribution that is broad in energy and sometimes shows time dispersion indicating acceleration at various altitudes up the field line. Such acceleration is not consistent with a purely electrostatic potential drop, and suggests a wave heati...

Auroral Plasma Lines: A First Comparison of Theory and Experiment

Excitation of Alfvén impulse by the anomalous resistance onset on the auroral field lines

The onset of anomalous resistance in a layer on auroral field lines is shown to be accompanied by the excitation of an Alfvénic impulse (AI). The generated AI marks the transition of the global magnetosphere-ionosphere instability into an explosive phase with positive feedback. The spatial structure of this impulse both in space and on the ground has been described analytically and numerically ...

Auroral field-aligned currents by incoherent scatter plasma line observations in the E region

The aim of the Swedish-Japanese EISCAT campaign in February 1999 was to measure the ionospheric parameters inside and outside the auroral arcs. The ion line radar experiment was optimised to probe the E-region and lower F-region with as high a speed as possible. Two extra channels were used for the plasma line measurements covering the same altitudes, giving a total of 3 upshifted and 3 downshi...