HR: 15:20h
AN: SA23B-06    [Abstracts]
TI: Magnetosphere Ionosphere Atmosphere Coupling at Altitudes Below 250 km.
AU: * Heelis, R A
EM: heelis@utdallas.edu
AF: University of Texas at Dallas, MS FO22 PO Box 830688, Richardson, TX 75083-0688 United States
AU: Sojka, J J
EM: fasojka@sojka.cass.usu.edu
AF: Utah State University, 4405 Old Main Hill, Logan, UT 84322-4405 United States
AB: Between 100 and 500 km the upper atmosphere is a relatively good electrical conductor transverse to the magnetic field. In this region transverse currents can be generated and or conducted and electric polarization fields can be created that affect the electrodynamics of the entire volume threaded by the magnetic field. Due to the high electric conductivity of the region it plays a key role in the coupling of the atmosphere to the magnetosphere and the solar wind. Coupling studies indicate that this region is important in controlling the efficiency of the coupling between the magnetosphere and the solar wind and in determining the spatial extent and temporal persistence of electric fields in the magnetosphere. In this region there can exist large vertical and horizontal gradients in the ion density and in the neutral winds that drive currents. These gradients will produce internal polarization electric fields, non-uniformities in the Ohmic dissipation rates and resulting non-uniformities in the dynamics and composition of the atmosphere and ionosphere. But despite these complications, in most coupling studies the region is regarded as one, or at most two, horizontal conducting layers. This limiting approach is taken due in large part to our inability to specify the nature of any coherent structures in the region. Discovering how spatial and temporal structures are produced in the lower ionosphere and atmosphere and how they evolve is a preeminent challenge for the ionosphere thermosphere community. We will describe some of the impacts of spatial and temporal structures in the lower ionosphere and atmosphere and approaches, such as the Geospace Electrodynamic Connections mission, to obtaining the required information about them.
DE: 2409 Current systems (2721)
DE: 2419 Ion chemistry and composition (0335)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005