HR: 1340h
AN: P33B-1300    [Abstracts]
TI: Venus Express Magnetometer Observations: Global Vortices at the Ionopause
AU: * Balikhin, M A
EM: m.balikhin@sheffield.ac.uk
AF: Centre for Signal Processing and Complex Systems, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
AU: Pope, S A
EM: S.a.pope@sheffield.ac.uk
AF: Centre for Signal Processing and Complex Systems, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
AU: Zhang, T L
EM: tielong.zhang@oeaw.ac.at
AF: Space Res. Inst., Schmiedlstrasse, 6, Graz, 8042, Austria
AB: The interaction of the solar wind with Venus differs from the terrestrial case because Venus does not posses intrinsic magnetic field. This leads to the direct interaction between the fast flowing solar wind and the Venusian ionosphere at the ionopause. Venus Express(VEX) magnetometer data show nonlinear steepened surface waves at the ionopause. In some crossings it shows that nonlinear evolution of these waves leads to the formation of vortices. We argue that these waves and vortex structures are the result of the Kelvin-Helmholtz instability excited due to the shear velocity profile at the ionopause. Analysis of VEX observations show that these vortices should contribute to the ionospheric and atmospheric escape and the formation of plasma clouds observed in previous experiments.
DE: 5421 Interactions with particles and fields
DE: 5435 Ionospheres (2459)
DE: 7839 Nonlinear phenomena (4400, 6944)
DE: 7852 Solitons and solitary waves (4455)
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting