Using STEREO/EUVI to Study Active Region Magnetic Fields
Abstract
We examine the effect of linear transformations on the misalignment between model magnetic fields and coronal loops in active regions, as observed with STEREO/EUVI on three separate occasions between April 30 and May 19, 2007. We perform stereoscopic triangulation of some 100 EUVI loops in each active region, and identify the tangent vectors along every loop. Using magnetogram information from SOHO/MDI we compute a 3D potential field and interpolate the magnetic field vector at every position along the EUVI loops. The angle between the loop tangent vector and the magnetic field vector provides a measure of the misalignment angle between the observed field configuration and the model. We then transform the field in a way that preserves the divergence-free condition while injecting electric currents into the system. With this modified field we repeat our calculation of the misalignment angles between the magnetic field vectors and the EUV loop tangent vectors, quantifying the improvement of the transformed magnetic field model. Results of this type of magnetic modeling are presented for three active regions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFMSH13B1523S
- Keywords:
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- 7509 Corona;
- 7524 Magnetic fields;
- 7549 Ultraviolet emissions