AbstractWe evaluate two prevailing substorm models with an event of plasma flow reversal from tailward to Earthward detected by Cluster at the downstream distance of ∼19 RE in the magnetotail during a substorm on August 22, 2001. We use the unique capability of Cluster measurements in determining gradients to examine the associated current density, Lorentz force, and current dissipation/dynamo term. In association with plasma flow reversal, it is found that (1) there was no clear quadrupole magnetic perturbation signature, (2) the x-component of the Lorentz force did not change sign, (3) the y-component of the product of the current density and the electric field was occasionally negative indicative of a dynamo effect, and (4) the timing sequence of flow reversal from the Cluster configuration did not match tailward motion of a single plasma flow source. These observations are consistent with the near-Earth initiation model for substorms with multiple current disruption sites moving progressively tailward near the late stage of substorm expansion.


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    Title :

    Evaluation of substorm models with Cluster observations of plasma flow reversal in the magnetotail


    Contributors:
    Lui, A.T.Y. (author) / Zheng, Y. (author) / Rème, H. (author) / Dunlop, M.W. (author) / Gustafsson, G. (author)

    Published in:

    Advances in Space Research ; 41 , 10 ; 1611-1618


    Publication date :

    2007-05-15


    Size :

    8 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English