Direct observation of closed magnetic flux trapped in the high-latitude magnetosphere
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Authors
Fear, R.C.
Milan, S.E.
Maggiolo, R.
Fazakerley, A.N.
Douras, I.
Mende, S.B.
Discipline
Physical sciences
Subject
aurora
latitude
magnetic field
magnetosphere
magnetotail
plasma
satellite imagery
Audience
Scientific
Date
2014Metadata
Show full item recordDescription
The structure of Earth's magnetosphere is poorly understood when the interplanetary magnetic field is northward. Under this condition, uncharacteristically energetic plasma is observed in the magnetotail lobes, which is not expected in the textbook model of the magnetosphere. Using satellite observations, we show that these lobe plasma signatures occur on high-latitude magnetic field lines that have been closed by the fundamental plasma process of magnetic reconnection. Previously, it has been suggested that closed flux can become trapped in the lobe and that this plasma-trapping process could explain another poorly understood phenomenon: the presence of auroras at extremely high latitudes, called transpolar arcs. Observations of the aurora at the same time as the lobe plasma signatures reveal the presence of a transpolar arc. The excellent correspondence between the transpolar arc and the trapped closed flux at high altitudes provides very strong evidence of the trapping mechanism as the cause of transpolar arcs.
Citation
Fear, R.C.; Milan, S.E.; Maggiolo, R.; Fazakerley, A.N.; Douras, I.; Mende, S.B. (2014). Direct observation of closed magnetic flux trapped in the high-latitude magnetosphere. , Science, Vol. 346, Issue 6216, 1506-1510, DOI: 10.1126/science.1257377.Identifiers
scopus: 2-s2.0-84919458999
Type
Article
Peer-Review
Yes
Language
eng