HR: 0830h
AN: SM11C-1185    [PDF]
TI: Measurement of Thermal Electrons at Rocket Altitudes in Nightside Active Aurora
AU: * MacDonald, E A
EM: eamd2@cisunix.unh.edu
AF: Space Science Center, University of New Hampshire, Durham, NH 03820
AU: Lynch, K A
EM: kristina.lynch@dartmouth.edu
AF: Space Science Center, University of New Hampshire, Durham, NH 03820
AU: Lynch, K A
EM: kristina.lynch@dartmouth.edu
AF: Dept. of Physics and Astronomy, Dartmouth College, Hanover, NH 03755
AU: Arnoldy, R
EM: roger.arnoldy@unh.edu
AF: Space Science Center, University of New Hampshire, Durham, NH 03820
AU: Kintner, P
EM: paul@ece.cornell.edu
AF: Dept. of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14850
AU: Klatt, E
EM: klatt@ece.cornell.edu
AF: Dept. of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14850
AU: LaBelle, J
EM: James.W.LaBelle@dartmouth.edu
AF: Dept. of Physics and Astronomy, Dartmouth College, Hanover, NH 03755
AU: Samara, M
EM: marilia@dartmouth.edu
AF: Dept. of Physics and Astronomy, Dartmouth College, Hanover, NH 03755
AB: On January 14, 2002 the SIERRA sounding rocket was launched from Alaska into active substorm expansion aurora and reached 735 km altitude. For the first time, measurements of the cold ionospheric population in darkness were made by the UNH thermal electron detector (TED). At these middle altitudes, understanding this population is important because the thermal electrons can carry currents coupling the collisional atmosphere and the magnetospheric auroral source. The considerable instrumental difficulties with this measurement will be thoroughly discussed including the effects of spacecraft potential, Debye length, applied skin bias, and surface charging. Recent efforts to verify instrument response through laboratory testing will be highlighted. During flight, the TED instrument yielded thermal temperatures between 0.1 - 0.4 eV. We will examine how the measured population agrees with a Maxwellian-shaped distribution through independent comparisons of density as derived by the TED and also an HF wave receiver plasma frequency measurement. The physics of the ambient cold population and its interaction with auroral mechanisms will be emphasized throughout.
DE: 2407 Auroral ionosphere (2704)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2455 Particle precipitation
DE: 2467 Plasma temperature and density
DE: 2494 Instruments and techniques
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting