*Authors:*
Groth, Clinton P. T.
<
http://adsabs.harvard.edu/cgi-bin/author_form?author=Groth,+C&fullauthor=Groth,%20Clinton%20P.%20T.&charset=UTF-8&db_key=AST>;
De Zeeuw, Darren L.
<
http://adsabs.harvard.edu/cgi-bin/author_form?author=De+Zeeuw,+D&fullauthor=De%20Zeeuw,%20Darren%20L.&charset=UTF-8&db_key=AST>;
Gombosi, Tamas I.
<
http://adsabs.harvard.edu/cgi-bin/author_form?author=Gombosi,+T&fullauthor=Gombosi,%20Tamas%20I.&charset=UTF-8&db_key=AST>;
Powell, Kenneth G.
<
http://adsabs.harvard.edu/cgi-bin/author_form?author=Powell,+K&fullauthor=Powell,%20Kenneth%20G.&charset=UTF-8&db_key=AST>
*Journal:*
Journal of Geophysical Research, Volume 105, Issue A11, p. 25053-25078
(JGR Homepage <
http://www.agu.org/pubs/pubs.html>)
*Publication Date:*
11/2000
*Origin:*
AGU
*AGU Keywords:*
Solar Physics, Astrophysics, and Astronomy
*Abstract Copyright:*
(c) 2000: American Geophysical Union
*DOI:*
10.1029/2000JA900093 <
http://dx.doi.org/10.1029/2000JA900093>
*Bibliographic Code:*
2000JGR...10525053G
Abstract
A parallel adaptive mesh refinement (AMR) finite-volume scheme for
predicting ideal MHD flows is used to simulate the initiation,
structure, and evolution of a coronal mass ejection (CME) and its
interaction with the magnetosphere-ionosphere system. The simulated CME
is driven by a local plasma density enhancement on the solar surface
with the background initial state of the corona and solar wind
represented by a newly devised ``steady state'' solution. The initial
solution has been constructed to provide a reasonable description of the
time-averaged solar wind for conditions near solar minimum: (1) the
computed magnetic field near the Sun possesses high-latitude polar
coronal holes, closed magnetic field flux tubes at low latitudes, and a
helmet streamer structure with a neutral line and current sheet; (2) the
Archimedean spiral topology of the interplanetary magnetic field is
reproduced; (3) the observed two-state nature of the solar wind is also
reproduced with the simulation yielding fast and slow solar wind streams
at high and low latitudes, respectively; and (4) the predicted solar
wind plasma properties at 1 AU are consistent with observations.
Starting with the generation of a CME at the Sun, the simulation follows
the evolution of the solar wind disturbance as it evolves into a
magnetic cloud and travels through interplanetary space and subsequently
interacts with the terrestrial magnetosphere-ionosphere system. The
density-driven CME exhibits a two-step release process, with the front
of the CME rapidly accelerating following the disruption of the near-Sun
closed magnetic field line structure and then moving at a nearly
constant speed of ~560 km/s through interplanetary space. The CME also
produces a large magnetic cloud (>100R_S across) characterized by a
magnetic field that smoothly rotates northward and then back again over
a period of ~2 days at 1 AU. The cloud does not contain a sustained
period with a strong southward component of the magnetic field, and, as
a consequence, the simulated CME is somewhat ineffective in generating
strong geo-magnetic activity at Earth. Nevertheless, the simulation
results illustrate the potential, as well as current limitations, of the
MHD-based space weather model for enhancing the understanding of coronal
physics, solar wind plasma processes, magnetospheric physics, and space
weather phenomena. *Such models will provide the foundation for future,
more comprehensive space weather prediction tools.
