A wave-like evolution of polar cap ionization patches associated with wider distributed nightside reconnection
Abstract
A train of large-scale patches of ionization has been observed in the polar cap ionosphere during strong southward IMF conditions within the main phase of a moderate geomagnetic storm. The patches are formed at equatorward of cusp region througn the cusp dynamics and enter the polar cap through "cusp throat". The formation of these patches is also associated with clear enhancement of cross polar cap potential. When the IMF By is positive, the patches have been obliquely stretched like a wavefront in the polar cap propagating to dusk sectors, and exit the polar cap in wide MLT regions (15-24 MLT). While, when the IMF By turn small negative, a tongue of ionization (TOI) or a very large-scale patch is formed and almost straightly propagates to midnight sector. These observations suggest that the patches evolve along the streamlines, which are gradually widened and duskward tilted in the nightside sectors of the ionospheric convection pattern. This convection pattern is modulated by widely happened nightside reconnection in the magnetotail during southward IMF with positive By component.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMSM51C2756Z
- 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