The underlying causes of
coronal eruptions, or coronal
mass ejections (CMEs), must
be determined if we are
going to use solar
observations to make
successful predictions of
space weather storms at 1
AU. These causes can be
studied with large-scale or
global MHD coronal models
in time-dependent form. The
SAIC coronal model, and
another MHD model at NRL,
are capable of exploring the
possible causes of CMEs.
Concepts based on
photospheric field behavior
are readily tested using the
Stanford/Lockheed
magnetograph data and
these computational tools. It
will be necessary to simulate
both the speed of the CME
and its magnetic field
configuration to make a
successful storm prediction.
The top figure shows an
SAIC model simulation of field
line behavior during a CME.
In this case the simulated
CME was initiated by
reversing the polarity of the
photospheric magnetic field
under an idealized sheared
coronal arcade structure. The
figure below shows an
alternative model from NRL
where a CME was initiated by
emerging flux in a
quadrupolar coronal field
configuration. Indeed,
several CME genesis
scenarios may apply in
nature. The bottom figure
shows simulated integrated
line-of-sight densities, as
might be viewed with a
coronagraph, for the SAIC
CME model from a different
perspective.
Click on the images to the left to view the corresponding animation.
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