HR: 11:35h
AN: SA32A-05    [Abstracts]
TI: MHD and kinetic modeling analysis of high-altitude photoelectron observations at Mars
AU: * Liemohn, M W
EM: liemohn@umich.edu
AF: University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109 United States
AU: Ma, Y
EM: yingjuan@umich.edu
AF: University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109 United States
AU: Kozyra, J U
EM: jukozyra@umich.edu
AF: University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109 United States
AU: Nagy, A F
EM: anagy@umich.edu
AF: University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109 United States
AU: Frahm, R A
EM: rfrahm@swri.edu
AF: Southwest Research Institute, PO Drawer 28510, San Antonio, TX 78284 United States
AU: Winningham, J D
EM: david@cluster.space.swri.edu
AF: Southwest Research Institute, PO Drawer 28510, San Antonio, TX 78284 United States
AU: Sharber, J R
EM: jsharber@swri.edu
AF: Southwest Research Institute, PO Drawer 28510, San Antonio, TX 78284 United States
AU: Barabash, S V
EM: stas@irf.se
AF: Swedish Institute of Physics, POB 812, Kiruna, S-98128 Sweden
AU: Lundin, R N
EM: rickard.lundin@irf.se
AF: Swedish Institute of Physics, POB 812, Kiruna, S-98128 Sweden
AU: Team, T
EM: stas@irf.se
AF: Swedish Institute of Physics, POB 812, Kiruna, S-98128 Sweden
AB: The Electron Spectrometer (ELS) instrument of the ASPERA-3 package on the Mars Express satellite has observed photoelectron energy spectra up to apoapsis (~ 10,000 km). The characteristic photoelectron shape of the spectrum is sometimes seen well above the ionosphere in the evening sector across a wide range of near-equatorial latitudes. Two numerical models are used to analyze the characteristics of these high-altitude photoelectrons. The first is a global, multi-species MHD code that produces a 3-d representation of the magnetic field and bulk plasma values around Mars. It is used here to examine the possibility of magnetic connectivity between the high-altitude flanks and the subsolar ionosphere. It is found that some field lines in this region are draped IMF lines while others are open field lines, connected to both the IMF and the crustal magnetic field sources. The second model is a kinetic electron transport model that calculates the electron velocity space distribution along a non-uniform magnetic field line. It is used here to simulate the high-altitude ELS measurements. It is found that there are systematic differences in the electron distributions depending on the type of field line (open or draped).
DE: 2459 Planetary ionospheres (5435, 5729, 6026, 6027, 6028)
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
DE: 5435 Ionospheres (2459)
DE: 5443 Magnetospheres (2756)
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly