HR: 0800h
AN: SM51A-0357    [Abstracts]
TI: Rocket Observations of Narrowband Structured HF Waves near $f_{pe}$ in the Auroral Ionosphere
AU: * Samara, M
EM: marilia.samara@dartmouth.edu
AF: Dartmouth College, 6127 Wilder Lab, Hanover, NH 03755 United States
AU: LaBelle, J
EM: james.labelle@dartmouth.edu
AF: Dartmouth College, 6127 Wilder Lab, Hanover, NH 03755 United States
AU: Kletzing, C
EM: craig-kletzing@uiowa.edu
AF: University of Iowa, Van Allen Hall, Iowa, IA 52242 United States
AU: Bounds, S
EM: scott-bounds@uiowa.edu
AF: University of Iowa, Van Allen Hall, Iowa, IA 52242 United States
AB: The Rocket Auroral Correlator Experiment (RACE) sounding rocket was launched into active aurora from Poker Flat, Alaska on February 6th, 2002, at 9:38:51 UT. The payload reached an apogee of 922km at approximately 550 seconds. We report high resolution measurements of structured HF wave emissions in the overdense plasma ($f_{pe}>f_{ce}$) observed after apogee at about 650 seconds after launch. They are narrowband emissions, and of relatively short duration, that occur near the $f_{pe}$ cut off. They have been observed previously and termed "HF chirps", with amplitudes around 1 mV/m and durations of about 100 ms (McAdams et. al., 1999). These new data provide the opportunity to study HF chirps in greater detail and compile an atlas of their characteristics, since preliminary anlysis reveals that they have diverse features unlike the first observations by McAdams et. al. \bibitem[{\textit{McAdams and LaBelle}(1999)}]{McAdams-99} McAdams, K.~L., and J.~LaBelle (1999), Narrowband structrure in HF waves above the electron plasma frequency in the auroral ionosphere, \textit{Geophys. Res. Lett.}, \textit{26}, 1825.
DE: 2407 Auroral ionosphere (2704)
DE: 2411 Electric fields (2712)
DE: 2483 Wave/particle interactions
DE: 2487 Wave propagation (6934)
DE: 2704 Auroral phenomena (2407)
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting