HR: 11:10h
AN: SM22A-04    [Abstracts]
TI: The Influence of Magnetospheric Substorms on SuperDARN Backscatter: a Statistical Assessment
AU: * Wild, J A
EM: j.wild@lancaster.ac.uk
AF: Department of Communication Systems, Lancaster University, Infolab21, Lancaster, LA1 4WA, United Kingdom
AU: Grocott, A
EM: a.grocott@ion.le.ac.uk
AF: Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom
AB: With the advent of NASA's THEMIS mission, worldwide scientific attention is focused upon the investigation of magnetospheric substorms. The SuperDARN array of high-frequency coherent-scatter ionospheric radars are certain to play a key role in upcoming space- and ground-based studies. However, the level of SuperDARN backscatter, crucial for the production of geophysical data products, has been reported to sometimes reduce in the vicinity of the substorm-associated auroral bulge. We have therefore investigated the impact of magnetospheric substorms upon SuperDARN radar backscatter during approximately 3000 substorms and find that the global level of scatter maximizes at about the time of substorm onset. In the nightside ionosphere, backscatter in the region poleward of ~70° magnetic latitude is reduced slightly, with radar echoes shifting to lower latitudes. An examination of the frequency-dependence of nightside backscatter evolution during substorms reveals that the higher frequency bands offer the best relative backscatter performance in the period immediately after substorm expansion phase onset. Detailed findings and recommendations for future SuperDARN operations will be presented.
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2788 Magnetic storms and substorms (7954)
DE: 2794 Instruments and techniques
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting