Narrow auroral arc notes

June 1, 2012

magnetic bottle: pitch angle distribution vs. mirror height equipotential lines -> parallel E-field (Stephen Knight 1970) -> Large scale, dull auroral arc

• inertial alfven wave connection to parallel E-field

fine scale arcs assosciated with Farley-Buneman instabilities, GPS scintillation

energy to produce electron-ion pair ionization potential ~ 18 eV takes on average ~ 35 eV

energy deposition physics

single particle motion, 3 adiabatic invariants, Debye length, two fluid vector potential

Alfven wave can couple to whistler mode

Auroral emissions: Bohr model of atom. have to release energy gap between orbitals (work function). Vibrational modes

Ions: closure current electrons: field aligned current

Inertial alfven wave: electron mass matters due to phase speed > speed of light F=ma inertial limit inerital lag – prevents group velocity from exceeding speed of light

λ_e = c / ω_pe electron skin depth confines wave

Auroral emissions:

Björn Gustavsson Ph.D. thesis discusses briefly specifics of four major auroral emission lines.

Matthew Zettergren Ph.D. thesis discusses kinetic reactions resulting in auroral emissions, upon which my Ph.D. research is based.

Auroral width:

• Borovsky 1993 “Auroral arc thicknesses as predicted by various theories”, JGR: Space Physics.
• Chaston 2003 “Width and brightness of auroral arcs driven by inertial Alfven waves”, JGR: Space Physics.

Books:

• Chen
• Kivelson and Russell
• Cravens
• Nagey