Journal cover Journal topic
Annales Geophysicae An open-access journal of the European Geosciences Union
Ann. Geophys., 27, 895-903, 2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.
23 Feb 2009
Concerning the occurrence pattern of flux transfer events on the dayside magnetopause
D. G. Sibeck Code 674, NASA/GSFC, 8800 Greenbelt Rd, Greenbelt, MD 20771, USA
Abstract. We present an analytical model for the magnetic field perturbations associated with flux transfer events (FTEs) on the dayside magnetopause as a function of the shear between the magnetosheath and magnetospheric magnetic fields and the ratio of their strengths. We assume that the events are produced by component reconnection along subsolar reconnection lines with tilts that depend upon the orientation of the interplanetary magnetic field (IMF), and show that the amplitudes of the perturbations generated during southward IMF greatly exceed those during northward IMF. As a result, even if the distributions of magnetic reconnection burst durations/event dimensions are identical during periods of northward and southward IMF orientation, events occurring for southward IMF orientations must predominate in surveys of dayside events. Two factors may restore the balance between events occurring for northward and southward IMF orientations on the flanks of the magnetosphere. Events generated on the dayside magnetopause during periods of southward IMF move poleward, while those generated during periods of northward IMF slip dawnward or duskward towards the flanks. Due to differing event and magnetospheric magnetic field orientations, events that produce weak signatures on the dayside magnetopause during intervals of northward IMF orientation may produce strong signatures on the flanks.

Citation: Sibeck, D. G.: Concerning the occurrence pattern of flux transfer events on the dayside magnetopause, Ann. Geophys., 27, 895-903,, 2009.
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