A solar storm observed from the Sun to Venus using the STEREO, Venus Express, and MESSENGER spacecraft

Authors Organisations
  • A. P. Rouillard(Author)
    University of Southampton
    Rutherford Appleton Laboratory
  • J. A. Davies(Author)
    Rutherford Appleton Laboratory
  • R. J. Forsyth(Author)
    Imperial College London
  • N. P. Savani(Author)
    Imperial College London
  • N. R. Sheeley(Author)
    Naval Research Laboratory
  • A. Thernisien(Author)
    Naval Research Laboratory
  • T. -L Zhang(Author)
    Austrian Academy of Sciences
  • R. A. Howard(Author)
    Naval Research Laboratory
  • B. Anderson(Author)
    Johns Hopkins University
  • C. M. Carr(Author)
    Imperial College London
  • S. Tsang(Author)
    University College London
  • M. Lockwood(Author)
    University of Southampton
    Rutherford Appleton Laboratory
  • C. J. Davis(Author)
    Rutherford Appleton Laboratory
  • R. A. Harrison(Author)
    Rutherford Appleton Laboratory
  • D. Bewsher(Author)
    Rutherford Appleton Laboratory
  • M. Fränz(Author)
  • S. R. Crothers(Author)
  • C. J. Eyles(Author)
  • D. S. Brown(Author)
  • I. Whittaker(Author)
  • M. Hapgood(Author)
    Rutherford Appleton Laboratory
  • A. J. Coates(Author)
    University College London
  • G. H. Jones(Author)
  • Manuel Grande(Author)
  • R. A. Frahm(Author)
    Southwest Research Institute
  • J. D. Winningham(Author)
    Southwest Research Institute
Type Article
Original languageEnglish
Article numberA07106
JournalJournal of Geophysical Research: Space Physics
Issue numberA7
Publication statusPublished - Jul 2009
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The suite of SECCHI optical imaging instruments on the STEREO-A spacecraft is used to track a solar storm, consisting of several coronal mass ejections (CMEs) and other coronal loops, as it propagates from the Sun into the heliosphere during May 2007. The 3-D propagation path of the largest interplanetary CME (ICME) is determined from the observations made by the SECCHI Heliospheric Imager (HI) on STEREO-A (HI-1/2A). Two parts of the CME are tracked through the SECCHI images, a bright loop and a V-shaped feature located at the rear of the event. We show that these two structures could be the result of line-of-sight integration of the light scattered by electrons located on a single flux rope. In addition to being imaged by HI, the CME is observed simultaneously by the plasma and magnetic field experiments on the Venus Express and MESSENGER spacecraft. The imaged loop and V-shaped structure bound, as expected, the flux rope observed in situ. The SECCHI images reveal that the leading loop-like structure propagated faster than the V-shaped structure, and a decrease in in situ CME speed occurred during the passage of the flux rope. We interpret this as the result of the continuous radial expansion of the flux rope as it progressed outward through the interplanetary medium. An expansion speed in the radial direction of ∼30 km s−1 is obtained directly from the SECCHI-HI images and is in agreement with the difference in speed of the two structures observed in situ. This paper shows that the flux rope location can be determined from white light images, which could have important space weather applications.


  • solar wind