HR: 0800h
AN: P51B-1431    [Abstracts]
TI: Jovian Radio Burst Remote Sensing of Solar Wind Triggered Jovian Magnetospheric Activity: Ulysses Observations
AU: * MacDowall, R J
EM: robert.macdowall@nasa.gov
AF: NASA/GSFC, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 United States
AU: Desch, M D
EM: michael.d.desch@nasa.gov
AF: NASA/GSFC, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 United States
AU: Kaiser, M L
EM: michael.kaiser@nasa.gov
AF: NASA/GSFC, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 United States
AU: Reiner, M J
EM: reiner@urap.gsfc.nasa.gov
AF: NASA/GSFC, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 United States
AU: Reiner, M J
EM: reiner@urap.gsfc.nasa.gov
AF: The Catholic University of America, 620 Michigan Ave., NE, Washington, DC 20064 United States
AU: Forsyth, R J
EM: r.forsyth@imperial.ac.uk
AF: Imperial College, Space and Atmospheric Physics Group, The Blackett Laboratory, London, SW7 2BW United Kingdom
AU: McComas, D J
EM: dmccomas@swri.edu
AF: Southwest Research Institute, Instrumentation and Space Research Div., San Antonio, TX 78228 United States
AB: In 2003 and early 2004, the Ulysses spacecraft descended from high heliographic latitudes towards perihelion, bringing it relatively close to Jupiter. The geometry of this distant flyby (0.8 AU closest approach) caused Ulysses to spend more than 6 months above a jovicentric latitude of 50 deg at a range of less than 2 AU, while the spacecraft traversed a considerable range of Jovian local time (9 hrs to 17 hrs). During much of this time interval, Jupiter was intercepted each solar rotation by two corotating high density structures and sector boundaries. From the perspective of Ulysses, the radio response of the magnetosphere to a given corotating structure was the intensification of either Jovian broad-band kilometric (bKOM) emission or of a combination of emissions, including bKOM and Jovian narrow-band kilometric (nKOM) emission. Such enhancements have been studied previously with Voyager, Ulysses, Galileo, and Cassini radio data. For Ulysses observations in 1991 and 1992, in particular, the typical scenario was brightening in the Jovian bKOM emission, followed by a sudden cessation of the bKOM emission and an onset of an nKOM "event" that lasted for some 120 hours (Reiner et al., 2000). For the sequences of events in 2003-2004, the two episodes per solar rotation; driven by high speed streams and/or current sheet crossing, clearly have different morphologies. In this presentation, variations in solar wind kinetic pressure and magnetic field direction (measured by Ulysses) are analyzed as triggers of Jovian magnetospheric activity, indicated by the intense radio emissions. Several intervals when magnetic clouds intercept Jupiter and produce Jovian radio events are also examined.
DE: 5737 Magnetospheres (2756)
DE: 6220 Jupiter
DE: 6954 Radio astronomy
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting