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Multipoint observations of nightside auroral activity: the Cascades2 sounding rocket mission . Dartmouth College Cornell University NASA Wallops Flight Facility University of New Hampshire NSROC University of Alaska Fairbanks PFISR
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Multipoint observations of nightside auroral activity: the Cascades2 sounding rocket mission Dartmouth College Cornell University NASA Wallops Flight Facility University of New Hampshire NSROC University of Alaska Fairbanks PFISR KTH-Stockholm Poker Flat Research Range SRI SSL/UCB K A Lynch, Dartmouth College 2009 Fall AGU SM53D-05
Outline • Cascades2 mission and goals • March 2009 PFRR nightside event • Three science topics • PBI case study (Themis, PFISR, cameras, in situ observations) • Measurement of DCE shear frequencies • Deconvolving a tall-ray event • Summary and ongoing efforts
Science objectives and questions (1) Does dynamic aurora move with respect to the background ionosphere? How much? Does it matter? Proper motion and evolution of arc structures… (2) 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? Quantifying shears… (3) Alfven waves carry disturbances and changes down to and through the auroral zone, giving us structured and dancing aurora. They are pretty: do they matter? Are these structures significant for magnetosphere/ionosphere coupling? Do direct observations of these motions validate theories and models? Deconvolving a tall-ray event…
Bo PFRR PFISR Toolik Kaktovic C2 array: E and B along Bo e- across Bo Fast e- down Bo Image down Bo Ground cameras Radar GPS position and timing
Event: 20 March 2009 11:11:11UT apogee Near local magnetic midnight 564 km apogee Repeating PBI event
PBI case study • First two, unaccelerated (or minimally accelerated) Maxwellians • Different from “typical” inverted-V arcs, but discrete • 3rd, wave accelerated, field-aligned
Array size: 4-6 km along B ~0.5 km across B Structure: footpoint 100-200 km altitude 2 km wide/13 km/sec = 0.15sec
Other ongoing • Magnetometer deconvolution • Ion motion up and down field line • Further development of onboard camera • Plasma density measurements • Stereo camera imaging • Multiple-point measurements separating d/dx from d/dt….3 payloads, 4 payloads, 5 payloads, …10?