Preliminary Results from the CASCADES 2 Sounding Rocket

Paul Kintner, Eric Lundberg, Cornell U.Kristina Lynch, Meghan Mella, Dartmouth C.

Nicolay Ivchencko, Hanna Dahlgren, RITMarc Lessard, UNH

Hans Stenbaek-Nielsen, UAF-GI

CASCADES 2 Overview• Launched 20 March 2009 at 11:04:00 UT– Apogee of 564 km over north coast of Alaska– Interesting physics 468-436 km altitude downleg at about

11:14:00 UT (600 sec)• Conditions– Poleward boundary intensification – Rayed auroral arc– Cold thermosphere and lowered ionosphere (solar min.)

• Preliminary results– Large Alfvénic electric fields (± 100 mV/m)– Dispersed downward electron signatures– Ion acceleration appearing as downward conic

Toolik Video

12 m tip-to-tip

Total Electric Field

Full flight

-180 -90 0 90 180 pitch angle

en

erg

y [

eV

] 2

2

0

200

-40 -20 0 20 40 v-perp [km/sec]

-40

-20

0

20

40

Maxwellian, 3eV Tpar, 30eV Tperp, -20 km/sec downward shift

Same, plotted as JEon pitch-energy axes

-180 -90 0 90 180 pitch angle

en

erg

y [

eV

] 2

2

0

200

-180 -90 0 90 180 pitch angle

en

erg

y [

eV

] 2

2

0

200

Electron Plasma Waves

Science Questions to Investigate• Does dynamic aurora move with respect to the background

ionosphere? How much? Consequences?• What is the spatial as compared to temporal variation of

auroral parameters like B and E? What does this mean for theories of energy transfer?

• Alfven waves carry disturbances and changes down to and through the auroral zone producing structured aurora. Are these structures significant for magnetosphere/ionosphere coupling? Do direct observations of these motions validate theories and models?

Science Questions to Investigate• Does dynamic aurora move with respect to the background

ionosphere? How much? Does it matter? • What is the spatial as compared to temporal variation of

auroral parameters like B and E? What does this mean for theories of energy transfer?

• Alfven waves carry disturbances and changes down to and through the auroral zone, giving us structured and dancing aurora. Are these structures significant for magnetosphere/ ionosphere coupling? Do direct observations of these motions validate theories and models?

Science Questions to Investigate• Are the Alfven waves related to the heated ion

distribution? Do density irregularities nonlinearly move Alfven waves to shorter transverse wave lengths which cause transverse ion acceleration?

• What electric field accelerates both electrons and ions downward? Times scales likely matter. Does downward ion acceleration increase the ion transverse energy

Back up slides