HR: 13:45h
AN: SA23B-02    [Abstracts]
TI: Nighttime E-region Electron Density Profiles Measured During the EQUIS II Campaign at Kwajalein Atoll
AU: * Rowland, D E
EM: drowland@lepefi.gsfc.nasa.gov
AF: NASA / GSFC, NASA Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Pfaff, R F
EM: Robert.F.Pfaff@nasa.gov
AF: NASA / GSFC, NASA Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Fourre, R
EM: fourrere@att.net
AF: NASA / GSFC, NASA Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Kudeki, E
EM: erhan@uiuc.edu
AF: UIUC, University of Illinois, Urbana-Champaign, Urbana-Champaign, IL United States
AU: Steigies, C T
EM: steigies@physik.uni-kiel.de
AF: IEAP, CAU, Christian Albrechts University, Kiel, Germany
AU: Chau, K
EM: chau@geo.igp.gob.pe
AF: JRO, IGP, Jicamarca Radio Observatory, Peru
AU: Sarango, M
EM: sarango@jro.igp.gob.pe
AF: JRO, IGP, Jicamarca Radio Observatory, Peru
AB: The EQUIS II nighttime E-region rocket and radar measurements were made in order to improve our understanding of the electrodynamics associated with density gradients, neutral wind shear, and enhanced electric fields that develop post-sunset in the near-equatorial region. Four rocket experiments were launched on two separate nights in September, 2004 from Kwajalein Atoll (9.4° N, 167.5° E), while simultaneous E-region radar observations were made with the ALTAIR radar. The focus of this presentation are the electron density profiles measured by two instrumented rockets as they passed through the unstable region on the upleg and downleg. Each rocket used two Langmuir probes and an impedance probe of a new design to measure both the absolute electron density and small-scale density fluctuations with spatial scales on the order of one meter. The impedance probe returned measurements from 7 kHz to 4 MHz, using a new design that excited the plasma using a pseudo-white-noise generator, allowing for an altitude resolution of approximately 40 meters. These impedance curves allow determination of the electron density from the identification of the upper hybrid frequency. In addition, evidence is presented that the impedance probe observed the lower-frequency "series" resonance which is dependent on the electron temperature. Data from the Langmuir probes, a beacon experiment, and the impedance probe are compared and the resulting density profiles are examined to estimate their contribution to the observed electric field irregularities via the gradient-drift and other instabilities.
DE: 2415 Equatorial ionosphere
DE: 2439 Ionospheric irregularities
DE: 2467 Plasma temperature and density
DE: 2471 Plasma waves and instabilities
DE: 2494 Instruments and techniques
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly