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Prob, %

12. 12. Prob, %. 4. 3. 2. 1. 0. 00. 00. Winter. Summer. 06. 18. Probability of observing downward field-aligned electron energy flux >10 mW/m 2 in winter and summer hemispheres. Newell et al. , 1996. Three Characteristic Acceleration Regions.  Direction of J ||.

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Prob, %

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  1. 12 12 Prob, % 4 3 2 1 0 00 00 Winter Summer 06 18 Probability of observing downward field-aligned electron energy flux >10 mW/m2 in winter and summer hemispheres. Newell et al., 1996

  2. Three Characteristic Acceleration Regions  Direction of J|| Carlson et al. ‘01

  3. Alfvén Wave Induced Outflow Carlson et al. ‘01

  4. Average Thermal Plasma Density Near 1RE Altitude (Polar EFI) Johnson et al. ‘01

  5. Polarization  Field-Aligned Current Ionospheric Feedback Lysak Atkinson ’70, Sato ‘78

  6. Two-fluid Alfvénic Response of the Magnetosphere Electron parallel momentum v||e- electron parallel speed;IC- electron collision frequency; AR- effective collision frequency representing wave-particle interactions. Density continuity Current continuity ρi- ion Larmour radius.

  7. Coupling to Auroral E-Region Density Continuity Equation n = n0 + n1E-region plasma number density; S1 = n02ionization source maintaining equilibriumn0 j||field-aligned current; recombination coefficient. Current Continuity Equation SP , SHheight-integrated Pedersen and Hall conductances.

  8. Ionospheric Alfvén Resonator Field Line Resonator “Feedback” Unstable Alfvén Waves Two resonant cavities IAR Growth Rate  larger for – smaller P – larger E – larger k Pokhotelov ‘02

  9. equator 125 s 220 s ENS ionosphere 235 s 141 s E LayerJ  J  Ne + – Ne2 + – P + – E –+ Stable?yesno 251 s 157 s 266 s 173 s 281 s 188 s 297 s 204 s L = 7.25 8.25 670 mV/m Feedback Instability Ionospheric Alfvén Resonator

  10. Animation sequence from 0 < t < 300 s ENS (mV/m) L = 8.25 7.25

  11. Occurrence of Upward Ion Beams Near 1RE Altitude (Polar TIMAS) Collin et al. ‘98

  12. Auroral Electrodynamics Opgenoorth et al. ‘02

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