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Space Technology 5 measurements of auroral field‐aligned current sheet motion
Author(s) -
Wang Y.,
Le G.,
Slavin J. A.,
Boardsen S. A.,
Strangeway R. J.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl035986
Subject(s) - earth's magnetic field , geodesy , current (fluid) , current sheet , magnetic field , geology , field (mathematics) , range (aeronautics) , geophysics , magnitude (astronomy) , current density , physics , computational physics , geometry , materials science , astrophysics , mathematics , magnetohydrodynamics , oceanography , quantum mechanics , pure mathematics , composite material
During the 90‐day Space Technology 5 (ST‐5) mission, a total of 2535 auroral field‐aligned current (FAC) signatures were identified. Of these 1030 were suitable to be modeled as semi‐infinite current sheets aligned with L‐shells and moving with constant speed in the north or south directions (hereafter called FAC speed). FAC speeds were found to range from −1 to 1 km/s with larger mean magnitude during intervals of higher geomagnetic activity. At ST‐5 altitudes, ∼300 to 4500 km, the median relative errors in FAC thickness and current density, when stationary FAC is assumed, are 4%. When the ST‐5 FAC speed determinations are extrapolated along the IGRF‐10 magnetic field lines, these errors increase to 23% and 24% at 4 R E , and 65% and 124% at 8 R E , respectively.