Polar rain aurora
Article first published online: 31 OCT 2007
Copyright 2007 by the American Geophysical Union.
Geophysical Research Letters
Volume 34, Issue 20, October 2007
How to Cite
2007), Polar rain aurora, Geophys. Res. Lett., 34, L20114, doi:10.1029/2007GL031602., , and (
- Issue published online: 31 OCT 2007
- Article first published online: 31 OCT 2007
- Manuscript Accepted: 4 OCT 2007
- Manuscript Revised: 27 SEP 2007
- Manuscript Received: 7 AUG 2007
- polar rain;
- keV electrons
 Global FUV auroral imagers (IMAGE/SI-13 and DMSP/SSUSI) observed, for the first time, two similar auroral events in the southern polar cap due to intense (keV) polar rain electrons from the solar wind as observed by DMSP and Geotail. Such an aurora is called polar rain aurora. The polar rain aurora could fill the dayside polar cap initially and developed a dawn-dusk alignment while they moved anti-sunward. The associated IMF Bz was mostly southward. The IMF Bx changed from negative to positive for the first event and stayed positive for the second event. The strong IMF By was associated with the two events. The dawn-dusk alignment of polar rain aurora might be due to the dawn-dusk aligned magnetic flux tubes in the magnetosheath caused by the dominant IMF By and modulation of the keV electrons by the nonoscillatory drift mirror waves and pitch angle diffusion via the electron cyclotron instability.