Nonlinear force-free extrapolation of SDO/HMI vector magnetograms in to the corona
Abstract
SDO/HMI provides us high resolution full disk measurements of the photospheric magnetic field vector.We compute the field in the higher layers of the solar atmosphere from the measured photospheric field under the assumption that the corona is force-free. However, those measured data are inconsistent with the above force-free assumption. Therefore, one has to apply some transformations dubbed preprocessing to these data before nonlinear force-free extrapolation codes can be applied. Our force-free code is based on an optimization principle and takes the spherical geometry of the sun in to account. Untill now, these extrapolations were applied only to a small surface area of the Sun so that cartesian geometry could be applied. We carry out both full disk computations as well as computations of active regions. The code has been well tested with model equilibria and used with the ground based observations from SOLIS. We plan to show first Nonlinear force-free coronal magnetic fields extrapolated from SDO/HMI in comparison with the coronal plasma in SDO/HMI.
- Publication:
-
38th COSPAR Scientific Assembly
- Pub Date:
- 2010
- Bibcode:
- 2010cosp...38.2866T