GUVI Biblio




Notice:

  • Clicking on the DOI link will open a new window with the original bibliographic entry from the publisher.
  • Clicking on a single author will show all publications by the selected author.
  • Clicking on a single keyword, will show all publications by the selected keyword.





Solar illumination control of ionospheric outflow above polar cap arcs



AuthorMaes, L.; Maggiolo, R.; De Keyser, J.; Dandouras, I.; Fear, R.; Fontaine, D.; Haaland, S.;
Keywordscold ion outflow; ion upflow; polar cap arc; polar ionosphere; polar wind; solar illumination
Abstract

We measure the flux density, composition, and energy of outflowing ions above the polar cap, accelerated by quasi-static electric fields parallel to the magnetic field and associated with polar cap arcs, using Cluster. Mapping the spacecraft position to its ionospheric foot point, we analyze the dependence of these parameters on the solar zenith angle (SZA). We find a clear transition at SZA between \~94\textdegree and \~107\textdegree, with the O+ flux higher above the sunlit ionosphere. This dependence on the illumination of the local ionosphere indicates that significant O+ upflow occurs locally above the polar ionosphere. The same is found for H+, but to a lesser extent. This effect can result in a seasonal variation of the total ion upflow from the polar ionosphere. Furthermore, we show that low-magnitude field-aligned potential drops are preferentially observed above the sunlit ionosphere, suggesting a feedback effect of ionospheric conductivity.

Year of Publication2015
JournalGeophysical Research Letters
Volume
Number of Pages
Section
Date Published03/2015
ISBN
URLhttp://doi.wiley.com/10.1002/2014GL062972
DOI10.1002/2014GL062972