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Read Full Article (file size: 3052920 bytes) Cited by
GEOPHYSICAL RESEARCH LETTERS,
VOL. 34,
L20114,
doi:10.1029/2007GL031602,
2007
Polar rain aurora
Yongliang Zhang
Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
Larry J. Paxton
Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
Anthony T. Y. Lui
Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA
Abstract
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.
Received 7
August
2007;
accepted 4
October
2007;
published 31
October
2007.
Keywords: polar rain;
aurora;
keV electrons.
Index Terms: 2704 Magnetospheric Physics: Auroral phenomena (2407); 2776 Magnetospheric Physics: Polar cap phenomena; 2784 Magnetospheric Physics: Solar wind/magnetosphere interactions; 2455 Ionosphere: Particle precipitation; 0310 Atmospheric Composition and Structure: Airglow and aurora.
Read Full Article (file size: 3052920 bytes) Cited by
Citation: Zhang, Y., L. J. Paxton, and A. T. Y. Lui
(2007),
Polar rain aurora,
Geophys. Res. Lett.,
34,
L20114,
doi:10.1029/2007GL031602.
Copyright 2007 by the American Geophysical Union.
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