HR: 11:50h
AN: SM52A-07    [Abstracts]
TI: ULF Waves in the Cusp Region as Observed by the SERSIO Sounding Rocket and on the Ground at Barentsburg, Svalbard
AU: * Ellis, A T
EM: armin.ellis@unh.edu
AF: University of New Hampshire, Space Science Center Morse Hall, Durham, NH 03824 United States
AU: Lessard, M R
EM: marc.lessard@unh.edu
AF: University of New Hampshire, Space Science Center Morse Hall, Durham, NH 03824 United States
AU: Kintner, P
EM: paul@ece.cornell.edu
AF: Cornell Univeristy, Dept of Electrical Engineering Rhodes Hall, Ithaca, NY 14853 United States
AU: Klatt, E
EM: ek59@cornell.edu
AF: Cornell Univeristy, Dept of Electrical Engineering Rhodes Hall, Ithaca, NY 14853 United States
AU: Lynch, K
EM: kristina.lynch@dartmouth.edu
AF: Dartmouth College, Dept of Physics, Hanover, NH 03755 United States
AU: Moen, J
EM: j.i.moen@fys.uio.no
AF: University of Oslo, Dept of Physics P.O.Box 1048, Blindern, Oslo, N-0316 Norway
AU: Yahnin, A
EM: yahnin@pgi.kolasc.net.ru
AF: Polar Geophysical Institute, Apatity, Apatity, Murmansk, 184209 Russian Federation
AU: Oksavik, K
EM: kjellmar.oksavik@jhuapl.edu
AF: Johns Hopkins University, Applied Physics Lab 11100 Johns Hopkins Rd, Laurel, MD 20723 United States
AU: Ogawa, Y
EM: yogawa@stelab.nagoya-u.ac.jp
AF: Nagoya University, STE Lab, Nagoya, 464-8602 Japan
AB: The SERSIO (Svalbard EISCAT Rocket Study of Ion Outflows) sounding rocket was launched on the 18nd of January, 2004 into an intense dayside aurora event driven by a CME. This event was also recorded by many instruments including all sky cameras, magnetometers and the EISCAT radar network. The magnetic footprint of the trajectory passed within 150 km of Barentsburg, Svalbard, where an induction coil magnetometer recorded intense pulsations. On the SERSIO payload the DC electric field instrument, sampled at 1000 Hz, showed spectral power from DC to ~100 Hz, the classic signature of BBELF waves, which are thought to be electrostatic and to have short wavelengths. On the ground, however, induction coil magnetometers recorded broad band waves with frequencies up to only a few Hz (but well below the upper limit of the frequency response of the coils). Previous work has shown that in order for a wave to be observable from the ground, two conditions must be met: 1) the wave must be electromagnetic in nature above the ionosphere and 2) it must have a perpendicular wavelength greater than ~2 km. This constraint suggests that the waves observed by SERSIO are actually comprised of two separate populations, including electrostatic BBELF waves with short wavelengths and electromagnetic waves with significanty larger perpendicular wavelengths. In this study, we compare in-situ observations of these waves to those on the ground, in conjunction with a numerical model that estimates the minimum perpendicular wavelength required to propagate through the ionosphere. These results confirm the suggestion that the signature observed by SERSIO actually includes two separate wave modes.
DE: 2407 Auroral ionosphere (2704)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2481 Topside ionosphere
DE: 2487 Wave propagation (0689, 3285, 4275, 4455, 6934)
DE: 2706 Cusp
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005