The formation of large-scale current sheets within magnetic clouds

Owens, M. J. ORCID: https://orcid.org/0000-0003-2061-2453 (2009) The formation of large-scale current sheets within magnetic clouds. Solar Physics, 260 (1). pp. 207-217. ISSN 0038-0938 doi: 10.1007/s11207-009-9442-6

Abstract/Summary

Magnetic clouds are a class of interplanetary coronal mass ejections (CME) predominantly characterised by a smooth rotation in the magnetic field direction, indicative of a magnetic flux rope structure. Many magnetic clouds, however, also contain sharp discontinuities within the smoothly varying magnetic field, suggestive of narrow current sheets. In this study we present observations and modelling of magnetic clouds with strong current sheet signatures close to the centre of the apparent flux rope structure. Using an analytical magnetic flux rope model, we demonstrate how such current sheets can form as a result of a cloud’s kinematic propagation from the Sun to the Earth, without any external forces or influences. This model is shown to match observations of four particular magnetic clouds remarkably well. The model predicts that current sheet intensity increases for increasing CME angular extent and decreasing CME radial expansion speed. Assuming such current sheets facilitate magnetic reconnection, the process of current sheet formation could ultimately lead a single flux rope becoming fragmented into multiple flux ropes. This change in topology has consequences for magnetic clouds as barriers to energetic particle propagation.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/5814
Item Type	Article
Refereed	Yes
Divisions	No Reading authors. Back catalogue items
Uncontrolled Keywords	Coronal mass ejection - Energetic particle propagation - Magnetic cloud - Magnetic flux rope - Magnetic reconnection - Solar activity - Solar wind
Publisher	Springer Verlag
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