The Generation of Electric Potentials Responsible for the Acceleration of Auroral Electrons
- S.-I. Akasofu and
- J.R. Kan
Published Online: 26 MAR 2013
Copyright 1981 by the American Geophysical Union.
Physics of Auroral Arc Formation
How to Cite
Swift, D. W. (1981) The Generation of Electric Potentials Responsible for the Acceleration of Auroral Electrons, in Physics of Auroral Arc Formation (eds S.-I. Akasofu and J.R. Kan), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM025p0288
- Published Online: 26 MAR 2013
- Published Print: 1 JAN 1981
Print ISBN: 9780875900506
Online ISBN: 9781118664360
- Auroras—Addresses, essays, lectures
The acceleration of electrons responsible for the discrete and inverted-V aurora requires some processes for the creation of potential differences perpendicular to magnetic field lines in the magnetosphere. It is shown that the two-dimensional, E×B, turbulent cascade can be an effective mechanism for the generation of potential variations over a wide range of size scales perpendicular to magnetic field lines. It is also shown by means of two-dimensional particle simulations that plasma microinstabilities can inject energy into the E×B turbulent cascade and that microinstabilites generated by ion beams in the magnetosphere can generate potential variations of a magnitude sufficient to account for the energy of auroral electrons. These processes have a strong tendency toward directional isotropy, which is inconsistent with the preferred east-west alignment. It is suggested that the modified two-stream instability, excited by ions streaming across magnetic field lines through strongly magnetized electrons, may be the instability which generates auroral potentials. A compelling feature of this instability is that it should be excited in a region of magnetic merging, which would allow us to directly identify the presence of auroral arcs with magnetic merging taking place elsewhere along the field lines.