HR: 1330h
AN: SM13A-03    [Abstracts]
TI: High resolution measurements of Langmuir waves upstream of the Saturnian bow shock
AU: * Hospodarsky, G B
EM: george-hospodarsky@uiowa.edu
AF: The University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242 United States
AU: Kurth, W S
EM: william-kurth @uiowa.edu
AF: The University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242 United States
AU: Gurnett, D A
EM: donald-gurnett@uiowa.edu
AF: The University of Iowa, Department of Physics and Astronomy, Iowa City, IA 52242 United States
AU: Zarka, P
AF: Observatoire de Paris, Observatoire de Paris Meudon, Meudon, France
AU: Canu, P
AF: CETP/UVSQ, 38/40 rue du General Leclerc, Velizy, France
AU: Dougherty, M
AF: Blackett Laboratory, Imperial College, London, United Kingdom
AU: Jones, G H
AF: Jet Propulsion Laboratory, 4800 Oak Grove Road, Pasadena, CA 91109 United States
AU: Coates, A
AF: Mullard Space Science Laboratory, University College London, Holmbury St. Mary, United Kingdom
AU: Young, D T
AF: Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228 United States
AB: The Cassini spacecraft is currently in the fourth orbit of its four-year prime mission to study the Saturnian system. The Radio and Plasma Wave Science (RPWS) investigation is designed to study the radio emissions and plasma waves in the vicinity of Saturn. The RPWS instrument includes a wideband receiver (WBR) that provides high time and frequency resolution over a range of frequencies, allowing the fine structure of various radio and plasma waves to be examined. Langmuir waves produced upstream of the Saturnian bowshock were detected by Cassini during the approach to Saturn, and also during each of the first four orbits of Cassini The structure of the Langmuir waves detected by Cassini spans a broad range of time scales, from tens of minutes to structures with time scales of milliseconds. The large scale structure includes upshifts and downshifts in the frequency of the Langmuir waves, probably due to the location of Cassini in the Saturnian foreshock, and also variation in the frequency of the Langmuir wave emission related to density variations in the solar wind. The small scale structure includes beat-like waveforms suggestive of a non-linear process. The observed structures, both the large and the fine time scales, are very similar to the structure observed in Langmuir waves at Venus, Earth, and Jupiter. The characteristics of these waves will be examined and the distribution of their electric field amplitude will be determined. These results will be compared to the various theories of Langmuir wave production and propagation.
DE: 2154 Planetary bow shocks
DE: 2159 Plasma waves and turbulence
DE: 2772 Plasma waves and instabilities
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly