HR: 08:00h
AN: SA41A-01 INVITED     [Abstracts]
TI: The Linkage Between the Ionospheric Trough and Ring Current
AU: * Brandt, P C
EM: pontus.brandt@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins University, Laurel, MD 20723, United States
AU: Zheng, Y
EM: yihua.zheng@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins University, Laurel, MD 20723, United States
AU: Talaat, E
EM: elsayed.talaat@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins University, Laurel, MD 20723, United States
AU: Sotirelis, T
EM: tom.sotirelis@jhuapl.edu
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins University, Laurel, MD 20723, United States
AU: Foster, J C
EM: jcf@haystack.mit.edu
AF: MIT Haystack Observatory, Rt. 40, Westford, ma 01886, United States
AU: Erickson, P J
EM: pje@haystack.mit.edu
AF: MIT Haystack Observatory, Rt. 40, Westford, ma 01886, United States
AB: We present data-model investigations of how the ring current couples to the sub-auroral ionosphere. The ring current pressure distribution during storm and substorms is highly asymetrical and sets up the region 2 current system that closes through the sub-auroral ionosphere. Of particular interest is what happens in the so-called ionospheric trough region, which is a region in the evening ionosphere with extremely low conductance (few tenths of a mho). Observations show strong westward flows in the ionospheric trough (Sub-Auroral Polarization Stream - SAPS) and sometimes highly structured and variable. The Comprehensive Ring Current Model models the ring current by using the bounce averaged Boltzmann equation and allowing the ring current to close through the ionosphere. Our model ionosphere includes dayside and auroral conductance as well as semi-empirical representation of the trough conductance. By using realistic representations of the conductances we seek to explore how the ring current pressure distribution (and therefore the region 2 current system) is linked to the presence of the trough. We use data from the IMAGE satellite, the Millstone Hill and SuperDARN radar facilities.
DE: 2712 Electric fields (2411)
DE: 2730 Magnetosphere: inner
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2778 Ring current
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Aeronomy [SA]
MN: 2007 Joint Assembly