Abstract In the presence of a strong magnetic field (such as the geomagnetic field) the plasma tends to flow along the magnetic field lines, therefore in most ionospheric flow calculations the use of the gyrotropic approximation is justified. In the first part of this paper it is shown that the gyrotropic twenty moment approximation is equivalent to the gyrotropic sixteen moment approximation. The second part of the paper is devoted to the study of return current generated polar wind transients. Ionospheric return currents generate significant downward heavy ion flows in the topside ionosphere with peak values well exceeding 108 cm−2s−1. When the return current ceases the polar ionosphere rapidly returns to its previous equilibrium state. During the recovery phase of the return current event an upward propagating heavy ion transient is formed, which is mainly characterized by a relatively short O+ upwelling event. The H+ escape flux remains relatively constant (within 10–20%) during field-aligned current events.


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    Title :

    Time-dependent polar wind modeling


    Contributors:
    Gombosi, T.I. (author) / Nagy, A.F. (author)

    Published in:

    Publication date :

    1989-01-01


    Size :

    10 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Time-dependent polar wind modeling

    Gombosi, T. I. / Nagy, A. F. | NTRS | 1988





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    Gombosi, T. I. / Kerr, L. K. / Nagy, A. F. et al. | NTRS | 1992