umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The role of plasma slowdown in the generation of Rhea's Alfvén wings
Institute of Geophysics and Planetary Physics and Dept. of Earth, Planetary and Space Sciences, University of California at Los Angeles, CA, 90095, USA.
Space Sciences Laboratory, University of California, Berkeley, California, USA.
Umeå University, Faculty of Science and Technology, Department of Physics. Swedish Institute of Space Physics, Kiruna.ORCID iD: 0000-0002-5765-2806
Max Planck Institute, Göttingen, Germany.
Show others and affiliations
2017 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 122, no 2, 1778-1788 p.Article in journal (Refereed) Published
Abstract [en]

Alfvén wings are known to form when a conducting or mass-loading object slows down a flowing plasma in its vicinity. Alfvén wings are not expected to be generated when an inert moon such as Rhea interacts with Saturn’s magnetosphere, where the plasma impacting the moon is absorbed and the magnetic flux passes unimpeded through the moon. However, in two close polar passes of Rhea, Cassini clearly observed magnetic field signatures consistent with Alfvén wings. In addition, observations from a high-inclination flyby (Distance > 100 R Rh ) of Rhea on 3 June 2010 showed that the Alfvén wings continue to propagate away from Rhea even at this large distance. We have performed three-dimensional hybrid simulations of Rhea’s interaction with Saturn’s magnetosphere which show that the wake refilling process generates a plasma density gradient directed in the direction of corotating plasma. The resulting plasma pressure gradient exerts a force directed toward Rhea and slows down the plasma streaming into the wake along field lines. As on the same field lines, outside of the wake, the plasma continues to move close to its full speed, this differential motion of plasma bends the magnetic flux tubes, generating Alfvén wings in the wake. The current system excited by the Alfvén wings transfers momentum to the wake plasma extracting it from plasma outside the wake. Our work demonstrates that Alfvén wings can be excited even when a moon does not possess a conducting exosphere.

Place, publisher, year, edition, pages
2017. Vol. 122, no 2, 1778-1788 p.
National Category
Fusion, Plasma and Space Physics
Research subject
Space and Plasma Physics
Identifiers
URN: urn:nbn:se:umu:diva-131165DOI: 10.1002/2016JA023595ISI: 000397022900025OAI: oai:DiVA.org:umu-131165DiVA: diva2:1072193
Funder
Swedish National Space Board
Available from: 2017-02-07 Created: 2017-02-07 Last updated: 2017-04-12

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Lindkvist, Jesper
By organisation
Department of Physics
In the same journal
Journal of Geophysical Research - Space Physics
Fusion, Plasma and Space Physics

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 23 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf