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JOURNAL OF GEOPHYSICAL RESEARCH,
VOL. 110,
A09S09,
doi:10.1029/2004JA010938,
2005
Three-dimensional estimates of the coronal electron density at times of extreme solar activity
M. D. Butala
Department of Electrical and Computer Engineering, Coordinated Science Laboratory, University of Illinois at Urbana-Champaign,
Urbana, Illinois, USA
R. A. Frazin
Department of Electrical and Computer Engineering, Coordinated Science Laboratory, University of Illinois at Urbana-Champaign,
Urbana, Illinois, USA
F. Kamalabadi
Department of Electrical and Computer Engineering, Coordinated Science Laboratory, University of Illinois at Urbana-Champaign,
Urbana, Illinois, USA
Abstract
This paper presents quantitative three-dimensional (3-D) reconstructions of the electron density (Ne) in the solar corona between 1.14 and 2.7 solar radii (R
) formed from polarized brightness (pB) measurements made by the Mauna Loa Solar Observatory Mark-IV (Mk4) K-coronameter at
the time of the extreme solar events of October and November 2003. The 3-D reconstructions are made by a process called solar
rotational tomography that exploits the view angles provided by solar rotation during a 2-week period. Although this method
is incapable of resolving dynamic evolution on timescales of less than about 2 weeks, a qualitative comparison of the reconstructions
to instantaneous Extreme ultraviolet Imaging Telescope images (EIT) shows good agreement between coronal holes, active regions,
and “quiet Sun” structures on the disk and their counterparts in the corona at 1.2 R
.
Received 30
November
2004;
accepted 22
March
2005;
published 30
September
2005.
Keywords: tomography;
electron density;
solar corona;
coronagraph;
image reconstruction.
Index Terms: 7509 Solar Physics, Astrophysics, and Astronomy: Corona; 7511 Solar Physics, Astrophysics, and Astronomy: Coronal holes; 6982 Radio Science: Tomography and imaging (7270, 8180); 7594 Solar Physics, Astrophysics, and Astronomy: Instruments and techniques.
Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 4312304 bytes)
Citation: Butala, M. D., R. A. Frazin, and F. Kamalabadi
(2005),
Three-dimensional estimates of the coronal electron density at times of extreme solar activity,
J. Geophys. Res.,
110,
A09S09,
doi:10.1029/2004JA010938.
Copyright 2005 by the American Geophysical Union.
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