Space Science Reviews ??, ???−???, 2009
© Springer Science+Business Media B.V
Interplanetary coronal mass ejections observed in the heliosphere:
3. Physical implications
T.A. Howard
Air Force Research Lab., National Solar Observatory, Sunspot, NM 88349
Dep. of Space Studies, Southwest Research Institute, Boulder, CO 80302
S.J. Tappin
Air Force Research Lab., National Solar Observatory, Sunspot, NM 88349
Abstract
We conclude the heliospheric image series with this third and final instalment,
where we consider the physical implications of our reconstruction of
interplanetary coronal mass ejections from heliospheric imagers. In Paper 1 a
review of the theoretical framework for the appearance of ICMEs in the
heliosphere was presented and in Paper 2 a model was developed that extracted
the three-dimensional structure and kinematics of interplanetary coronal mass
ejections directly from SMEI images. Here we extend the model to include STEREO
Heliospheric Imager data and reproduce the three-dimensional structure and
kinematic evolution of a single Earth-directed interplanetary coronal mass
ejection that was observed in November 2007. These measurements were made with
each spacecraft independently using leading edge measurements obtained from
each instrument. We found that when data from the three instruments was treated
as a single collective, we were able to reproduce an estimate of the ICME
structure and trajectory. There were some disparities between the modelled ICME
and the in situ data, and we interpret this as a combination of a slightly more
than spherically curved ICME structure and a corotating interaction region
brought about by the creation of a coronal hole from the CME eruption. This is
the first time evidence for such a structure has been presented and we believe
that it is likely that many ICMEs are of this nature.