HR: 1330h
AN: SM42B-0611    [PDF]
TI: An Evening Sector Ps 6 - Omega Band Event
AU: * Connors, M
EM: martinc@athabascau.ca
AF: Centre for Science, Athabasca University, 1 University Drive, Athabasca, AB T9S 3A3 Canada
AU: Donovan, E F
EM: eric@phys.ucalgary.ca
AF: Physics and Astronomy, University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4 Canada
AU: Syrjaesuo, M
EM: mikko@phys.ucalgary.ca
AF: Physics and Astronomy, University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4 Canada
AU: Greffen, M
EM: greffen@phys.ucalgary.ca
AF: Physics and Astronomy, University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4 Canada
AU: Mende, S B
EM: mende@ssl.berkeley.edu
AF: Space Sciences Laboratory, University of California, Berkeley, CA 94720 United States
AU: Russell, C T
EM: ctrussel@igpp.ucla.edu
AF: Institute of Geophysics, University of California, 405 Hilgard Ave, Los Angeles, CA 90095-1567 United States
AU: Jackel, B J
EM: bjackel@phys.ucalgary.ca
AF: Physics and Astronomy, University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4 Canada
AU: Trondsen, T
EM: trondsen@phys.ucalgary.ca
AF: Physics and Astronomy, University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4 Canada
AB: Ps 6 magnetic disturbances and associated optical forms known as omega bands are usually associated with the morning sector. The positive Y and transitional Z perturbations of the Ps 6 signal indicate localized regions of equatorward equivalent current in the auroral ionosphere, associated with the bright and vortical forms of the omega bands. The currents and optical forms drift sunward (eastward) at speeds typical of bulk convection. Evidence for similar phenomenology in the evening sector has been presented by Solovyev et al. (JGR 104, 28019, 1999). We confirm and enhance these results by presenting early results from the new Athabasca University Geophysical Observatory from July 27, 2003. These are magnetic perturbations from the UCLA magnetometer, and high time resolution optical imaging of associated omega bands from the all sky imager, which together make a prototype ground based networked observatory for the NASA THEMIS MIDEX mission. The signatures drift sunward (westward) and the magnetic perturbations feature negative Y and transitional Z indicating passage of poleward equivalent currents overhead. These results suggest that Kelvin-Helmholtz instablilities, the likely cause of the morning sector features, can also excite waves in the evening sector under appropriate circumstances.
DE: 2700 MAGNETOSPHERIC PHYSICS
DE: 2704 Auroral phenomena (2407)
DE: 2752 MHD waves and instabilities
DE: 2788 Storms and substorms
DE: 2794 Instruments and techniques
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting