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Abnormal Subauroral Ion Drifts (ASAID) and Pi2s During Cross‐Tail Current Disruptions Observed by Polar on the Magnetically Quiet Days of October 2003
Author(s) -
Horvath Ildiko,
Lovell Brian C.
Publication year - 2019
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2019ja026725
Subject(s) - physics , convection , quiet , polar , geophysics , plasma , substorm , computational physics , atmospheric sciences , astrophysics , mechanics , magnetosphere , astronomy , nuclear physics
In this study we further investigate the development of abnormal subauroral ion drifts/polarization streams (ASAID/ASAPS) during the magnetically quiet days of 9–10 October 2003. Our main aim is to provide direct observational evidence verifying that the Defense Meteorological Satellite Program F15 detected quiet‐time ASAID/ASAPS features developed due to the formation of a magnetospheric cold plasma ripple‐hot ring current interface. By utilizing multisatellite and multi‐instrument Cluster_C2, Polar, and Defense Meteorological Satellite Program observations, we investigate plasma rippling and Pi2 pulsation events. In good agreement with the associated empirical scenario of plasma sheet rippling, we demonstrate with various C2 and Polar events the following observational results. (1) The rippling of the plasma sheet's inner edge was related to the process of cross‐tail current disruption and its earthward propagation. (2) The Pi2 pulsation of the cross‐tail E Y field reversed the local convection flow when E Y was dawnward directed and thus caused plasma ripples while (3) energy was provided by the earthward flows' braking/deceleration. (4) The ASAID/ASAPS feature's underlying E Y is antisunward (or dawnward) and E Z is inward (or earthward). By tracking the cross‐tail current disruptions' tailward (by Cluster_C2) and earthward (by Polar) propagations, almost simultaneously, our results demonstrate also that the convection flows' local reversal by the dawnward E Y is a common feature of both the tailward and the earthward flows. This study demonstrates also, with multiple plasmapause and E Y detections made by Polar, the multiple and mixed occurrences of ASAID and SAID in the plasmasphere's rippled outer edge.