Study of the Open-Closed Boundary at the Polar Caps
Abstract
Knowledge of the location and dynamics of the magnetic field line open-closed boundary (OCB) provides insight to space physics processes such as substorms, particle precipitation events, and magnetospheric configuration. Prior studies have shown that determination of the OCB location can made by examining the ULF wave power in data from a latitudinal chain of ground-based magnetometers extending from the auroral zone into the deep polar cap. In this paper, we present both case studies and monthly climatologies, using ground magnetometer data from the Antarctic Automated Geophysical Observatories (AGOs), to characterize OCB behavior during minor geomagentic disturbances. En route, we find a preponderance of ULF activity associated with nightside plasma sheet injections. We discuss these synoptic ULF occurrences in light of recent work investigating ULF generation by drift-mirror instabilities at L < 10.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMSM51C2750G
- Keywords:
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- 3369 Thermospheric dynamics;
- ATMOSPHERIC PROCESSESDE: 2431 Ionosphere/magnetosphere interactions;
- IONOSPHEREDE: 2704 Auroral phenomena;
- MAGNETOSPHERIC PHYSICSDE: 2776 Polar cap phenomena;
- MAGNETOSPHERIC PHYSICS