Quantifying the relationship between the plasmapause and the inner boundary of small-scale field-aligned currents, as deduced from Swarm observations
This paper presents a statistical study of the equatorward boundary of small-scale field-aligned currents (SSFACs) and investigates the relation between this boundary and the plasmapause (PP). The PP data used for validation were derived from in situ electron density observations of NASA's...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-04-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/36/595/2018/angeo-36-595-2018.pdf |
| Summary: | This paper presents a statistical study of the equatorward boundary of
small-scale field-aligned currents (SSFACs) and investigates the relation
between this boundary and the plasmapause (PP). The PP data used for
validation were derived from in situ electron density observations of NASA's
Van Allen Probes. We confirmed the
findings of a previous study by the same authors obtained from the
observations of the CHAMP satellite SSFAC and the NASA IMAGE satellite PP
detections, namely that the two boundaries respond similarly to changes in
geomagnetic activity, and they are closely located in the near midnight MLT
sector, suggesting a dynamic linkage. Dayside PP correlates with the delayed
time history of the SSFAC boundary. We interpreted this behaviour as a direct
consequence of co-rotation: the new PP, formed on the night side, propagates
to the dayside by rotating with Earth. This finding paves the way toward an
efficient PP monitoring tool based on an SSFAC index derived from vector
magnetic field observations at low-Earth orbit. |
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| ISSN: | 0992-7689 1432-0576 |