Articles | Volume 27, issue 10
Ann. Geophys., 27, 3883–3897, 2009

Special issue: Three eyes on the Sun – multi-spacecraft studies of...

Ann. Geophys., 27, 3883–3897, 2009

  12 Oct 2009

12 Oct 2009

Signatures of interchange reconnection: STEREO, ACE and Hinode observations combined

D. Baker1, A. P. Rouillard2,3, L. van Driel-Gesztelyi1,4,5, P. Démoulin4, L. K. Harra1, B. Lavraud6,7, J. A. Davies3, A. Opitz6,7, J. G. Luhmann8, J.-A. Sauvaud6,7, and A. B. Galvin9 D. Baker et al.
  • 1University College London, Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, Surrey, RH5 6NT, UK
  • 2Space Environment Physics Group, School of Physics and Astronomy, University of Southampton, UK
  • 3Space Science and Technology Department, Rutherford Appleton Laboratory, UK
  • 4Observatoire de Paris, LESIA, FRE 2461(CNRS), F-92195 Meudon Principal Cedex, France
  • 5Konkoly Observatory of Hungarian Academy of Sciences, Budapest, Hungary
  • 6Centre d'Etude Spatiale des Rayonnements, Université de Toulouse (UPS), France
  • 7Centre National de la Recherche Scientifique, UMR 5187, Toulouse, France
  • 8Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA
  • 9Institute for the Study of Earth Oceans and Space, University of New Hampshire, Durham, NH 03824, USA

Abstract. Combining STEREO, ACE and Hinode observations has presented an opportunity to follow a filament eruption and coronal mass ejection (CME) on 17 October 2007 from an active region (AR) inside a coronal hole (CH) into the heliosphere. This particular combination of "open" and closed magnetic topologies provides an ideal scenario for interchange reconnection to take place. With Hinode and STEREO data we were able to identify the emergence time and type of structure seen in the in-situ data four days later. On the 21st, ACE observed in-situ the passage of an ICME with "open" magnetic topology. The magnetic field configuration of the source, a mature AR located inside an equatorial CH, has important implications for the solar and interplanetary signatures of the eruption. We interpret the formation of an "anemone" structure of the erupting AR and the passage in-situ of the ICME being disconnected at one leg, as manifested by uni-directional suprathermal electron flux in the ICME, to be a direct result of interchange reconnection between closed loops of the CME originating from the AR and "open" field lines of the surrounding CH.