Authors: Ellen Lee, Adriaan Van Ballegooijen, Ed DeLuca
Affiliation: Harvard-Smithsonian Center for Astrophysics
Energetic and complex solar magnetic fields are responsible for phenomena such
as flares and coronal mass ejections. While the magnetic field constrains and
energizes the coronal plasma, direct measurements of the field in the corona
are difficult. We present tools that allow for qualitative comparisons between
field extrapolation models and observed coronal loops. With these tools it will
be possible to find the field model that best fits the data.
Our model uses data from the Michelson Doppler Imager (MDI), Global Oscillation
Network Group (GONG), and the Transition Region and Coronal Explorer (TRACE).
We have developed a 3-D magnetic potential field model from line-of-sight MDI
and GONG magnetograms. These potential fields are aligned with TRACE 171 Angstrom
coronal loop images to find potential field deviations in the active region.
This model has imaging and loop-fitting capabilities to compare and analyze
such deviations. Our work has focused on the study of AR0130 on September 26th,
2002; AR0372 on June 7th, 2003; and AR 9575 on August 18th, 2001. We have studied
the field configurations in these regions and focused on the deviations from
the potential field model.
Further work will create a force-free model that can be compared to coronal
observations as well as develop the program to compare vector magnetograms to
the force-free model. This work has been supported by the XQT #NAS8-01003 and
AIA #SP02D4301R contracts.