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Detailed Reference Information |
Elsen, R.K. and Winglee, R.M. (1996). Mapping of magnetic field lines and auroral currents in the noon-midnight meridian. Journal of Geophysical Research 101: doi: 10.1029/96JA00863. issn: 0148-0227. |
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Time averaging provides a new way to study the output of global magnetospheric models and permits meaningful comparisons with ensemble-averaged satellite data and empirical magnetospheric models. A representative static configuration is prepared by time averaging the dynamic magnetic field generated by a two-dimensional global magnetospheric model in the noon-midnight meridian plane developed by Winglee [1994> that uses a modified two-fluid approximation. This two-fluid approach incorporates additional field-aligned currents not included in MHD but which are a vital component to the auroral current system in the noon and midnight sectors. The model produces a cyclical substorm while the IMF is southward, with a growth phase, an expansion phase, and a recovery phase. The resulting time-averaged configurations are studied parametrically using two series of runs that vary the solar wind dynamic ram pressure and the southward component of the interplanetary magnetic field, respectively. Although the time-dependent position of the X line can be as small as 13 RE, the average position of the X line exceeds 42 RE in all the cases studied. The auroral currents map to magnetic latitudes near 70¿ at midnight and move equatorward and intensify both for increased dynamic pressure and IMF BZ. These static magnetic configurations are compared with the T89M model of Tsyganenko [1989>. The peak tail current shows a variation similar to that in the T89M model but is about 30% less. Reducing the tail magnetic field of T89M to 70% of its original value gives more realistic values for BZ in the near-Earth tail and improves equatorial mapping of closed field lines in the tail. Increased activity causes a fixed point in the tail to map to a position more equatorward in the ionosphere within the simulations but to a position more poleward in T89M. ¿ American Geophysical Union 1996 |
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Abstract |
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Keywords
Magnetospheric Physics, Auroral phenomena, Magnetospheric Physics, Current systems, Magnetospheric Physics, Magnetospheric configuration and dynamics, Magnetospheric Physics, Magnetotail |
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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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