HR: 11:30h
AN: SM12A-05    [Abstracts]
TI: Narrowband Electromagnetic Emissions at Saturn Revisited: Cassini Observations
AU: * Kurth, W S
EM: william-kurth@uiowa.edu
AF: Univ. of Iowa, Dept. of Physics and Astronomy, Iowa City, IA 52242 United States
AU: Gurnett, D A
EM: donald-gurnett@uiowa.edu
AF: Univ. of Iowa, Dept. of Physics and Astronomy, Iowa City, IA 52242 United States
AU: Cecconi, B
EM: baptiste-cecconi@uiowa.edu
AF: Univ. of Iowa, Dept. of Physics and Astronomy, Iowa City, IA 52242 United States
AU: Hospodarsky, G B
EM: george-hospodarsky@uiowa.edu
AF: Univ. of Iowa, Dept. of Physics and Astronomy, Iowa City, IA 52242 United States
AU: Farrell, W M
EM: farrell@faltraz.gsfc.nasa.gov
AF: Goddard Space Flight Center, NASA, Greenbelt, MD 20771 United States
AU: Desch, M D
EM: mdesch@pop600.gsfc.nasa.gov
AF: Goddard Space Flight Center, NASA, Greenbelt, MD 20771 United States
AU: Kaiser, M L
EM: mkaiser@pop600.gsfc.nasa.gov
AF: Goddard Space Flight Center, NASA, Greenbelt, MD 20771 United States
AU: Canu, P
EM: patrick.canu@cetp.ipsl.fr
AF: CETP, UVSQ, Velizy, 78140 France
AB: Voyager observations revealed the existence of a complex set of narrowband electromagnetic emissions at Saturn in the frequency range of 3 to 30 kHz. These were found to be generated by mode conversion from electrostatic upper hybrid waves into ordinary mode electromagnetic waves which could freely propagate from the source. The frequency spacings of the narrowband emissions near the electron cyclotron frequency at Tethys, Dione, and Rhea suggested that these bands may be produced near these moons as part of their interaction with Saturn's magnetosphere. Cassini has now been in orbit at Saturn for seven months and has had an opportunity to further explore the low-frequency narrowband emissions. Similar emissions found over the ring system have been shown to be propagating in the Z-mode [Farrell et al., submitted, J. Geophys. Res., 2005], hence, would not propagate far from Saturn. However, other narrowband emissions observed by Cassini appear to be similar to those discovered with Voyager. Most of these, however, are found in the solar wind upstream of Saturn's bow shock. These emissions typically consist of a single band in the frequency range of ~6 to 8 kHz but sometimes are seen outside this range. More complex sets of bands are also seen, although not as often. In this paper we examine the new observations in an attempt to further understand the source of these emissions.
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
DE: 2772 Plasma waves and instabilities
DE: 5737 Magnetospheres (2756)
DE: 6954 Radio astronomy
DE: 7534 Radio emissions
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly