HR: 0800h
AN: SA31B-06    [Abstracts]
TI: Low frequency plasma waves at Mars: New results from the magnetosheath
AU: * Espley, J R
EM: Jared.Espley@gsfc.nasa.gov
AF: Planetary Magnetospheres Laboratory, Goddard Space Flight Center, Code 695.0 Goddard Space Flight Center, Greenbelt, MD 20771, United States
AU: Cloutier, P A
EM: pac@spacibm.rice.edu
AF: Dept. of Physics and Astronomy, Rice University, 6100 Main St. Rice University, Houston, TX 77005, United States
AU: Brain, D A
EM: brain@ssl.berkeley.edu
AF: Space Sciences Laboratory, Univ. of California, Berkeley, 7 Gauss Way, Univ. of California, Berkeley, Berkeley, CA 94270, United States
AU: Crider, D H
EM: crider@cua.edu
AF: Dept. of Physics, Catholic University of America, Catholic University of America c/o 106 Driftwood Dr., Gibsonville, NC 27249, United States
AU: Acuna, M H
EM: Mario.Acuna@nasa.gov
AF: Planetary Magnetospheres Laboratory, Goddard Space Flight Center, Code 695.0 Goddard Space Flight Center, Greenbelt, MD 20771, United States
AB: The interaction between the solar wind and the Martian ionosphere produces copious amounts of plasma waves and instabilities. We first review observations of low frequency (< 1 Hz) waves throughout the Martian system. We then focus specifically on new results regarding the high amplitude waves found in the magnetosheath region. The dayside magnetosheath waves are nonlinear (deltaB/|B| > 0.1) and are dominated by power near the local proton cyclotron frequency (~ 0.1 Hz). However, we also find intervals marked by strong spectral power at the local helium and oxygen gyrofrequencies. Some intervals also show strong bursts of wave activity bracketed by periods of relative calm; we speculate that these bursts could be related to plasma clouds detached from the Martian ionosphere. The nightside magnetosheath is comparatively quiet but intervals of ion cyclotron wave activity do exist.
DE: 5421 Interactions with particles and fields
DE: 5443 Magnetospheres (2756)
DE: 6225 Mars
DE: 7829 Kinetic waves and instabilities
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
SC: SPA-Aeronomy [SA]
MN: 2007 Joint Assembly