HR: 1330h
AN: SM42A-0590 INVITED     [PDF]
TI: IMF-Dependent Maps of High-Latitude Field-Aligned Currents Derived From {\O}rsted and CHAMP High-Precision Magnetic Field Measurements
AU: * Christiansen, F
EM: fch@dmi.dk
AF: Danish Meteorological Institute, Lyngbyvej 100, Copenhagen, DK-2100 Denmark
AU: Papitashvili, V O
EM: papita@umich.edu
AF: SPRL, University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109 United States
AB: Since their launch time, the {\O}rsted (1999-02-23) and CHAMP (2000-07-15) satellites have provided a bulk of high-precision geomagnetic field measurements made over both the northern and southern polar caps and covering all magnetic local times. As these observations now go for more than four years, these data are available for all variations in the Earth's dipole tilt (i.e., smoothly transitioning between the summer, equinox, and winter seasons) and for a variety of interplanetary magnetic field (IMF) conditions. In this study, we show a revised field-aligned currents empirical model (FACEM) for high-latitudes that was derived from the satellites data for quiet and moderate (but non-storm) IMF conditions. The model is mainly parameterized by the IMF strength and direction, as well as the Earth's dipole tilt angle. The model's detailed maps of the high-latitude field-aligned currents allow a researcher to follow evolution of the major field-aligned current systems (e.g., R0/R1/R2 and cusp currents) as the IMF vector rotates in the GSM Y-Z plane and the dipole tilt changes. Since the 23rd solar cycle shows a double maximum in 2000-2002, we attempt to deduce the solar activity effects on statistical distributions of the high-latitude field-aligned currents from 1999 and up to present time.
UR: http://maggy.engin.umich.edu/mist/limie.html
DE: 2409 Current systems (2708)
DE: 2411 Electric fields (2712)
DE: 2463 Plasma convection
DE: 2708 Current systems (2409)
DE: 2712 Electric fields (2411)
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting