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Detailed Reference Information |
Mei, Y., Crooker, N.U. and Siscoe, G.L. (1995). Cusp currents from ionospheric vorticity generated by gasdynamic and merging flow fields at the magnetopause. Journal of Geophysical Research 100: doi: 10.1029/94JA03370. issn: 0148-0227. |
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Cusp currents that arise from ionospheric vorticity generated by the combined merging outflow and gasdynamic flow fields at the magnetopause, as proposed by Saunders (1989), are quantified and compared with those calculated by Mei et al. (1994) from vorticity generated by mapping the solar wind electric field into a limited cusp region of the polar cap, as proposed in the synthesis view of Banks et al. (1984). The results are essentially identical for strong interplanetary magnetic field (IMF) By, thus demonstrating equivalence between mechanical and electrical descriptions of reconnection-driven convection. For southward IMF, however, the mechanical description yields weak cusp currents with dawn-dusk bipolarity, as deduced from early observations by Iijima and Potemra (1976), whereas the electrical description yields none. The bipolar currents arise from the diverging pattern of gasdynamic flow. The currents become unipolar as By increases and the asymmetry of the merging outflow dominates. Additional cusp currents in both models arise at kinks in the flow contours (additional ionospheric vorticity) around the border of the cusp region, owing to limiting the area of mapping from the magnetopause. The border currents form a bipolar pair that rotates around the circumference of the cusp as the IMF rotates in clock angle. They dominate the currents arising from vorticity within the cusp. ¿ American Geophysical Union 1995 |
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BACKGROUND DATA FILES |
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Abstract |
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Keywords
Ionosphere, Current systems, Magnetospheric Physics, Magnetopause, cusp, and boundary layers |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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