HR: 14:35h
AN: SM12B-04    [PDF]
TI: Remote Radio Sounding Science For JIMO
AU: * Green, J L
EM: james.green@nasa.gov
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Reinisch, B W
AF: Center for Atmospheric Research, University of Mass. Lowell, Lowell, MA 01854 United States
AU: Song, P
AF: Center for Atmospheric Research, University of Mass. Lowell, Lowell, MA 01854 United States
AU: Fung, S F
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Benson, R F
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Taylor, W W
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Cooper, J F
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Garcia, L
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Markus, T
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Gallagher, D
AF: NASA, Marshall Space Flight Center, Huntsville, AL 35812 United States
AU: Gogineni, P
AF: Remote Sensing Laboratory, University of Kanasas, Lawrence, KS 66045 United States
AB: Radio sounding of the Earth's topside ionosphere and magnetosphere is a proven technique from geospace missions such as the International Satellites for Ionospheric Studies (ISIS) and the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE). Application of this technique to the Jupiter Icy Moons Orbiter (JIMO) mission will provide unique remote sensing observations of the plasma and magnetic field environments, and the subsurface structures of Europa, Ganymede, and Callisto. Spatial structures of ionospheric plasma above the surfaces of these bodies will vary in response to magnetic field perturbations from magnetospheric plasma flows, ionospheric currents from ionization of sputtered surface material, and induced electric currents in salty subsurface oceans. Radio sounding at 3 kHz to 10 MHz will provide globally-determined electron densities necessary for the extraction of the oceanic current signals and will supplement in-situ plasma and magnetic field measurements. Long-range magnetospheric sounding, pioneered by the radio plasma imager (RPI) instrument on IMAGE, has provided electron density distributions along magnetic field lines and in radial directions on time scales of minutes. RPI has also been able to measure the entire electron plasma density distributions (in the orbit plane) of the Earth's polar cap and the plasmasphere within one pass of the spacecraft. In a similar manner, a radio sounder orbiting an icy moon would be able to measure the electron density along the magnetic field into each hemisphere and provide information on the Jovian magnetospheric background, the magnetospheric influences on the moon's ionospheres, and distortions of magnetic field line geometry from model predictions. The higher-power source available from JIMO would allow radio sounding transmissions at much higher powers than those used on ISIS or IMAGE making subsurface sounding of the Jovian icy moons possible at frequencies above the ionosphere peak plasma frequency from~5 MHz to 40 MHz. Subsurface variations in dielectric properties, can be investigated by radio sounding allowing the detection of dense and solid-liquid phase boundaries associated with oceans and related structures in overlying ice crusts.
DE: 2403 Active experiments
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
DE: 6929 Ionospheric physics (2409)
DE: 6994 Instruments and techniques
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting