Magnetic Dissipation in the Photosphere and Heating of the Corona
Abstract
Spatio-temporal dynamics of magnetic flux tubes in the photosphere of the Sun is thought to be a driving mechanism for energy built-up and energy release phenomena in the solar atmosphere. Turbulent flows in the photosphere braid and intertwine magnetic flux tubes creating a complex topology of the magnetic field in the corona which might result in the coronal heating. Intensity of turbulent flows of the magnetic flux tubes in the photosphere can be quantified by the magnetic energy dissipation rate, which is proportional to the averaged transverse velocity increment of the magnetic flux tubes. We suggest to derive 2D magnetic energy dissipation structures from line-of-sight magnetograms of active regions and then calculate the dissipation rate. Our findings for 104 active regions showed that the magnetic dissipation rate is in a good agreement (with the correlation coefficient close to 0.7) with the temperature and the emission measure of the corona. Our results present strong observational support for those coronal heating models that rely on random footpoint motions as an energy source to heat the corona above active regions.
- Publication:
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American Astronomical Society Meeting Abstracts #210
- Pub Date:
- May 2007
- Bibcode:
- 2007AAS...210.5301A