Interaction between kinetic ballooning perturbation and thin current sheet: Quasi-electrostatic field, local onset, and global characteristics
Abstract
We present observation of plasma waves in the current sheet across multiple THEMIS satellites in a substorm event on March 5, 2008. It is shown that the arrival of a kinetic ballooning perturbation interacts with the local current sheet to generate a quasi-electrostatic wave a few minutes before local onset, consistent with the prediction that the current sheet thins after the passage of a rarefaction wave. The propagation speed of current disruption front is found to be ~100 km/s, about a tenth of the fast mode speed. The observed pattern of interaction was constant across radial distances between 10 and 20 R E in the event reported. It is further proposed that the presence of the quasi-electrostatic field may change the local stability condition and induce local current disruption.
- Publication:
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Geophysical Research Letters
- Pub Date:
- October 2008
- DOI:
- 10.1029/2008GL035757
- Bibcode:
- 2008GeoRL..3520107L
- Keywords:
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- Magnetospheric Physics: Plasma waves and instabilities (2471);
- Magnetospheric Physics: Electric fields (2411);
- Magnetospheric Physics: Substorms;
- Magnetospheric Physics: Magnetic storms and substorms (7954)