Transcript
Keiling et al. ‘03
Visible FUV
Downward Poynting
Flux
UpwardPoynting Flux
Auroral Morphologyas seen in
AuroralLuminosity
Downward AlfvénPoynting Flux
Upward IonBeams
Liou et al. ‘97
Keiling et al. ‘03
Collin et al. ‘98
Auroral substorms & geomagnetic storms
Hypothesis (McFadden)
• Substorms deposit EM energy at low altitude.
• Ionosphere expands, promoting intense ion outflows.
• Stormtime electric fields force outflowing ions into near-earth plasmasheet.
• Betatron acceleration energizes earthward convecting ions.
• The now prodigious, energetic ions further energize the ring current, intensifying the storm.