Adv. in Geosciences: Solar Terrestrial 14, 161-181
Proc. AOGS 2007
Marc Duldig et al. (eds.)
© World Scientific Publishing Company
Coronal mass ejection reconstructions from interplanetary scintillation data
using a kinematic model: a brief review
M.M. Bisi, B.V. Jackson, P.P. Hick, A. Buffington and J.M. Clover
Center for Astrophysics and Space Sciences, Univ. of California San Diego
Abstract
Interplanetary scintillation (IPS) observations of multiple sources provide a
view of the solar wind at all heliographic latitudes from around 1 AU down
to coronagraph fields of view. These are used to study the evolution of the
solar wind and solar transients out into interplanetary space, and also the
inner-heliospheric response to co-rotating solar structures and coronal mass
ejections (CMEs). With colleagues at the Solar Terrestrial Environment Labo-
ratory (STELab), Nagoya University, Japan, we have developed near-real-time
access of STELab IPS data for use in space-weather forecasting. We use a three-
dimensional (3D) reconstruction technique that obtains perspective views of
solar co-rotating plasma and of outward-flowing solar wind crossing our lines
of sight from the Earth to the radio sources. This is accomplished by iteratively
fitting a kinematic solar wind model to the IPS observations. This 3D modelling
technique permits reconstructions of the density and speed structures
of CMEs and other interplanetary transients at a relatively coarse resolution.
These reconstructions have a 28-day solar-rotation cadence with 10° latitudinal
and longitudinal heliographic resolution for a co-rotational model, and a
one-day cadence and 20° latitudinal and longitudinal heliographic resolution
for a time-dependent model. These resolutions are restricted by the numbers
of lines of sight available for the reconstructions. When Solar Mass Ejection
Imager (SMEI) Thomson-scattered brightness measurements are used, lines of
sight are much greater in number so that density reconstructions can be better
resolved. Higher resolutions are also possible when these analyses are applied
to Ootacamund IPS data.