Carlson et al. ‘01 Three Characteristic Acceleration Regions

Carlson et al. ‘01 Alfvén Wave Induced Outflow

OUTFLOW Strangeway et al. ’02 Ponderomotive Lifting via Alfvén Waves a p|| = ¼  || (E  /B 0 ) 2 > GM E /r 2 for E  > 200 mV/m at 1000 km altitude

Li and Temerin ‘93 Ponderomotive Force (in a cold magnetized plasma)

Electrodynamic Coupling: Energy Dissipation ̶ Joule heating ̶ Current-Voltage relation (  Knight;  ?) ̶ Alfvén wave induced dissipation (?) Inertial Coupling: Mass Exchange ̶ Bulk outflows – polar wind ̶ Fractional outflows – energization (O + )

MIC LFM RCM LFM RCM LFM RCM TING MIC TING MIC seconds iterate minutes 1½-way LFM-RCM coupling w/ convergent, iterative, 2-way TING coupling LFM TING Empirical SWM Precip W ||, E 0 j || s m B RCM s TING M-I Coupler

minutes LFM TING SWM  B  2 >  j || s m B RCM s M-I Mass Coupler minutes Gravity = Ponderomotive Force at 1000-km altitude for n O+ = /m 3 and  B  = 80 nT MIC LFM RCM LFM RCM TING

 || = j || / K K = (n eff /n ps ) K Knight Banks and Holzer ‘69 Lemaire and Scherer ‘73 Field-Aligned Potential Drop Effects of Loss Cone n eff /n ps = 1 – (1 – B ps /B) ½ Bohm Criterion v ||i = c s into  || Neutral Gas Temperature in  T n Density Scale Height v ||e  B/n eff

Keiling et al. ‘03 VisibleFUV Downward Poynting Flux Upward Poynting Flux Auroral Morphology as seen in

Carlson et al. ‘01 Alfvénic Acceleration Regions

Intense, field-aligned Poynting fluxes flow earthward along the “lobe-plasma sheet” interface Polar FAST MPA UVI Lobe Plasma Sheet Polar Cap Auroral Zone Wygant et al. ’00

CISM All Hands Meeting 15 Sep 2003 LFM Low-Altitude Boundary TING High-Altitude Boundary

LFM Low-Altitude Boundary TING High-Altitude Boundary

“Quasi-static” Alfvén waves Alfvén-wave Lorentz Force

Banks and Holzer ‘69

Questions LFM BCs on , T? Inner boundary at r = constant where r  b  0  r  v E  0, i.e., v E has a component normal to the boundary. TING Ion energy and momentum equations? Same ion composition in E and F layers?

Grid Specification MM RCM TIM MIC CHART LEGEND Source of Numerical Data Magnetospheric Model Ring-Current Model Thermosphere-Ionosphere Model M-I Coupler “Variable A from MM on the MM grid and variable A from RCM on the RCM grid are interpolated onto the MIC grid” MIC RCMMM A

seconds minutes MIC MM RCM MM RCM MM RCM MIC 1½-way LFM-RCM coupling MM Empirical SWM Precip W ||, E 0 j || s B RCM s M-I Coupler

iterate minutes MM RCM MM RCM TIM MIC TIM MIC Convergent, iterative, 1-way TING coupling MM TIM Empirical SWM Precip W ||, E 0 j || s m B RCM s M-I Coupler

Auroral Electrodynamics Opgenoorth et al. ‘02

Ionospheric Feedback Atkinson ’70; Sato ‘78 Polarization  Field-Aligned Current

Two-fluid MHD model of the magnetosphere Electron parallel momentum equation Electron parallel momentum equation Density continuity equation Density continuity equation Current continuity equation Current continuity equation where v ||e - electron parallel speed; IC - electron collision frequency; AR - effective collision frequency representing the effects of plasma anomalous resistivity. where ρ i - ion Larmour radius.

Model of the auroral ionosphere Density Continuity Equation where n = n 0 + n 1 - plasma number density; - ionization source maintaining equilibrium density n 0 outside the region of auroral precipitations; j || - field-aligned current;  - recombination coefficient. Current Continuity Equation where  P and  H are height-integrated ionospheric Pedersen and Hall conductances.

“Feedback” Unstable Alfvén Waves Growth rate vs  P, E  and k  Two resonant cavities Large-Scale Resonator Small-Scale Resonator Pokhotelov ‘02

Feedback Instability Ionospheric Alfvén Resonator E Layer J   J    N e +–  N e 2 +–  P +–  E  – + Stable? yesno Streltsov and Lotko ‘ s 297 s 281 s 266 s 251 s 235 s 220 s 204 s 188 s 173 s 157 s 141 s E NS 670 mV/m equator ionosphere L =

Streltsov and Lotko ‘ mV/m E NS B EW nT distance, km (mV/m) 2 km k , km -1 (nT) 2 km PEPE PBPB Time Step = 297 s E NS B EW j  670 mV/m 270 nT 80  A/m 2 ionosphere equator “Satellite” Measurements

E NS (mV/m) L = IONOSPHERE 1 R E 44 R E Animation sequence from 0 < t < 300 s