Evaluation of substorm models with Cluster observations of plasma flow reversal in the magnetotail
2008 (English)In: Advances in Space Research, ISSN 0273-1177, Vol. 41, no 10, 1611-1618 p.Article in journal (Refereed) Published
We evaluate two prevailing substorm, models with an event of plasma flow reversal from tailward to Earthward detected by Cluster at the downstream distance of similar to 19 R-E in the magnetotail during a substorm. oil 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.
Place, publisher, year, edition, pages
2008. Vol. 41, no 10, 1611-1618 p.
substorm, current disruption
IdentifiersURN: urn:nbn:se:uu:diva-149374DOI: 10.1016/j.asr.2007.05.047ISI: 000256186300013OAI: oai:DiVA.org:uu-149374DiVA: diva2:405032