HR: 1340h
AN: P23A-0239    [Abstracts]
TI: Hydrogen Loss to the Solar Wind at Venus: Deductions from Proton Cyclotron Waves
AU: * Mayerberger, S S
EM: smayerberger@hotmail.com
AF: University of California Los Angeles, Institute of Geophysics and Planetary Physics, 405 Hilgard Avenue, Los Angeles, CA 90095-1567 United States
AU: Russell, C T
EM: ctrussell@igpp.ucla.edu
AF: University of California Los Angeles, Institute of Geophysics and Planetary Physics, 405 Hilgard Avenue, Los Angeles, CA 90095-1567 United States
AU: Blanco-Cano, X G
EM: xbc@geofisica.unam.mx
AF: Ciudad Universitaria, Institute of Geophysics, UNAM Coyoacan, Mexico, D.F 04510
AB: Proton cyclotron waves generated by ion pickup processes were detected at Mars, indicating the exospheric loss of hydrogen. Yet, these waves have never been reported at Venus, suggesting the possibility of different or less active loss mechanisms. However, a recent re-examination of the Pioneer Venus records, with more sophisticated data analysis techniques than were initially available, shows the presence of proton cyclotron waves up to at least 12 RV from the planet. A detailed wave analysis indicates that wave generation is controlled by the direction of the interplanetary magnetic field. These waves can provide insight into the nature of the pickup ion transport and acceleration processes at Venus.
DE: 6006 Atmospheres--evolution
DE: 6025 Interactions with solar wind plasma and fields
DE: 6225 Mars
DE: 6295 Venus
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting