HR: 11:05h
AN: SH51B-04    [PDF]
TI: Refining and understanding the auroral electrojet index AL
AU: Hoffman, R A
EM: Robert.A.Hoffman.1@gsfc.nasa.gov
AF: NASA-GSFC, CODE 696, Greenbelt, MD 20771 United States
AU: * Gjerloev, J W
EM: gjerloev@pop600.gsfc.nasa.gov
AF: NASA-GSFC, CODE 696, Greenbelt, MD 20771 United States
AU: Friel, M
EM: mfriel@gds.org
AF: NASA-GSFC, CODE 696, Greenbelt, MD 20771 United States
AU: Sugiura, M
EM: sugiura@jspan.kugi.kyoto-u.ac.jp
AF: Applied Research and Standard Division, 4-2-1 Nukui-Kitamachi Koganei, Tokyo, 184-8795 Japan
AU: Kamei, T
EM: toyo@kugi.kyoto-u.ac.jp
AF: World Data Center for Geomagnetism, Kyoto University, Kyoto, 606-01 Japan
AU: Frank, L A
EM: frank@IowaSP.Physics.UIowa.EDU
AF: Department of Physics and Astronomy, 405 Van Allen Hall, Iowa City, IA 52242-1479 United States
AU: Sigwarth, J B
EM: john-sigwarth@uiowa.edu
AF: Department of Physics and Astronomy, 405 Van Allen Hall, Iowa City, IA 52242-1479 United States
AB: A large number of ground based magnetometer stations and images are used to investigate a possible separation of the auroral electrojet index AL. Based on the two-component electrojet concept, the AL index is a measure of either the directly driven convection electrojet activity or the substorm current wedge electrojet activity. We presents results of a separation of the auroral electrojet index AL into two parts each monitoring these fundamentally different processes. Classical auroral substorms are selected using global auroral images and case studies as well as statistical results from more than 100 substorms will be presented. The statistical MLT distribution of the AL station location before and after the substorm onset was found by Gjerloev et al. [EOS, SM52B-05, F1179, 2002] to be well separated, thereby enabling a separation of the AL into ALw (wedge) and ALc (convection) using a simple MLT binning. The suggested separation of AL enables a simultaneous monitoring of the two westward electrojet components, thereby improving our ability to specify the space weather conditions as well as increasing our understanding of the temporal variability of these two electrojet components.
DE: 2704 Auroral phenomena (2407)
DE: 2708 Current systems (2409)
DE: 2712 Electric fields (2411)
DE: 2788 Storms and substorms
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting