J. Geophys. Res. 111 (A4), A04S91, 2006
© American Geophysical Union
Preliminary three-dimensional analysis of the heliospheric response to the 28
October 2003 CME using SMEI white-light observationse
B.V. Jackson, A. Buffington, P.P. Hick and X. Wang
Center for Astrophysics and Space Sciences, Univ. California San Diego, CA.
Inst. for Scientific Research, Boston College, MA.
The Solar Mass Ejection Imager (SMEI) has recorded the inner heliospheric
response in white-light Thomson scattering to the 28 October 2003 coronal
mass ejection (CME). This preliminary report shows the evolution of this
particular event in SMEI observations, as we track it from a first measurement
at approximately 20° elongation (angular distance) from the solar disk until
it fades in the antisolar hemisphere in the SMEI 180° field of view. The
large angle and spectrometric coronagraph (LASCO) images show a CME and an
underlying bright ejection of coronal material that is associated with an
erupting prominence. Both of these are seen by SMEI in the interplanetary
medium. We employ a three-dimensional (3-D) reconstruction technique that
derives its perspective views from outward flowing solar wind to reveal the
shape and extent of the CME. This is accomplished by iteratively fitting the
parameters of a kinematic solar wind density model to both SMEI white-light
observations and Solar-Terrestrial Environment Laboratory (STELab),
interplanetary scintillation (IPS) velocity data. This modeling technique
separates the true heliospheric signal in SMEI observations from background
noise and reconstructs the 3-D heliospheric structure as a function of time.
These reconstructions allow separation of the 28 October CME from other nearby
heliospheric structure and a determination of its mass. The present results are
the first utilizing this type of 3-D reconstruction with the SMEI data. We
determine an excess-over-ambient mass for the southward moving ejecta
associated with the prominence material of 7.1 × 1016 g and a total
mass of 8.9 × 1016 g. Preliminary SMEI white-light calibration
indicates that the total mass of this CME including possible associated nearby
structures may have been as much as ∼2.0 × 1017 g spread over much
of the earthward facing hemisphere.