HR: 1340h
AN: SM43C-1242    [Abstracts]
TI: Magnetic and Optical Signatures of Pc 3-4 Waves in Relation to Wave Transmission at South Pole, Antarctica
AU: * Quick, S
EM: quick@augsburg.edu
AF: Augsburg College, 2211 Riverside Ave, Minneapolis, MN 55454 United States
AU: Engebretson, M
EM: engebret@augsburg.edu
AF: Augsburg College, 2211 Riverside Ave, Minneapolis, MN 55454 United States
AU: Posch, J
EM: posch@augsburg.edu
AF: Augsburg College, 2211 Riverside Ave, Minneapolis, MN 55454 United States
AU: Lessard, M
EM: marc.lessard@unh.edu
AF: University of New Hampshire, Morse Hall, Durham, NH 03824 United States
AU: Arnoldy, R
EM: roger.arnoldy@unh.edu
AF: University of New Hampshire, Morse Hall, Durham, NH 03824 United States
AU: Frey, H
EM: hfrey@ssl.berkeley.edu
AF: University of California, Space Sciences Lab, Berkeley, CA 94720 United States
AU: Mende, S
EM: mende@ssl.berkeley.edu
AF: University of California, Space Sciences Lab, Berkeley, CA 94720 United States
AU: Detrick, D
EM: detrick@uacr.umd.edu
AF: University of Maryland, Inst Physical Science & Tech, College Park, MD 20742 United States
AB: A significant unresolved question in regard to Pc 3-4 (7-100 mHz) waves is the means by which such waves propagate to the high-latitude dayside ionosphere from their presumed origin upstream of the Earth's bow shock. Suggested mechanisms include equatorial entry via compressional waves, direct wave entry through the cusp, and indirect near-cusp entry via modulated precipitation of energetic particles. To further examine the latter mechanism, a correlation study was performed using data from search coil magnetometers, zenith-viewing photometers (427.8 and 630.0 nm), and an all-sky camera located at South Pole, Antarctica over a 153 day span in the Austral Winter of 2003. A statistical study was conducted in which the number of occurrences of Pc 3-4 waves seen in the x and y magnetic field components as well as in the two photometer signals was plotted as a function of local time. This showed a broad peak around 10:30 MLT for the magnetometer data and a sharper peak at the same time for the optical data. We found that when magnetic and optical signatures of Pc 3-4 pulsations were present at the same frequency and time, a brightened band in the poleward portion of the all-sky imager was present, most prominently at 630.0 nm. Such brightening was not seen when magnetic signatures of Pc 3-4 were present without corresponding optical pulsations. Selected events will be studied further to determine characteristic energy of precipitating particles and test whether their modulations are sufficient to produce the observed magnetic pulsations.
DE: 2407 Auroral ionosphere (2704)
DE: 2483 Wave/particle interactions (7867)
DE: 2706 Cusp
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005