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<div dir="ltr"><font face="tahoma">FYI - our latest paper is on the solar archives at</font></div>
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<div dir="ltr"><a href="http://solar.physics.montana.edu/cgi-bin/eprint/index.pl?entry=18486">http://solar.physics.montana.edu/cgi-bin/eprint/index.pl?entry=18486</a></div>
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<div dir="ltr"><font face="tahoma">Abstract:</font></div>
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<div dir="ltr"><strong><font size="4" face="Helvetica">A<font size="3" face="Calibri"> Rapid, Manual Method to Map Coronal-Loop Structures of an Active Region Using Cubic Bezier Curves and Its Applications to Misalignment Angle Analysis</font></font></strong><font size="3" face="Calibri">
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<div dir="ltr"><font size="3" face="Calibri">G. Allen Gary, Qiang<a></a> Hu<a></a>, and Jong<a></a> Kwan Lee</font></div>
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<div dir="ltr"><font size="3" face="Calibri">A rapid and flexible manual method is described which maps individual coronal loops of a 2D<a></a> EUV<a></a> image as Bezier curves using only four points per loop. Using the coronal loops as surrogates of magnetic-field
lines, the mapping results restrict the magnetic-field models derived from extrapolations of magnetograms<a></a> to those admissible and inadmissible via a fitness parameter. We outline explicitly how the coronal loops can be employed in constraining competing
magnetic-field models by transforming 2D<a></a> coronal-loop images into 3D<a></a> field lines. The magnetic-field extrapolations must satisfy not only the lower boundary conditions of the vector field, the vector magnetogram<a></a>, but also must have a set
of field lines that satisfies the mapped coronal loops in the volume, analogous to an upper boundary condition. This method uses the minimization of the misalignment angles between the magnetic-field model and the best set of 3D<a></a> field lines that match
a set of closed coronal loops. The presented method is an important tool in determining the fitness of magnetic-field models for the solar atmosphere. The magnetic-field structure is crucial in determining the overall dynamics of the solar atmosphere.
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