Detection of Flux Emergence, Splitting, Merging, and Cancellation in the Quiet Sun
Abstract
We investigate the frequency of magnetic activities, namely flux emergence, splitting, merging, and cancellation, through an automatic detection in order to understand the generation of the power-law distribution of magnetic flux reported by Parnell et al. (2009). Quiet Sun magnetograms observed in the Na I 5896 Å line by the Hinode Solar Optical Telescope is used in this study. The longitudinal fluxes of the investigated patches range from ≈ 1017 Mx to ≈ 1019 Mx. Emergence and cancellation are much less frequent than merging and splitting. The time scale for splitting is found to be ≈ 33 minutes and independent of the flux contained in the splitting patch. Moreover magnetic patches split into any flux contents with an equal probability. It is shown that such a fragmentation process leads to a distribution with a power-law index -2. Merging has a very weak dependence on flux content, with a power-law index of only -0.33. These results suggest that (1) magnetic patches are fragmented by splitting, merging, and tiny cancellation; and (2) flux is removed from the photosphere through tiny cancellations after these fragmentations.
- Publication:
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4th Hinode Science Meeting: Unsolved Problems and Recent Insights
- Pub Date:
- May 2012
- DOI:
- 10.48550/arXiv.1102.1238
- arXiv:
- arXiv:1102.1238
- Bibcode:
- 2012ASPC..455..169I
- Keywords:
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- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 8 pages, 4 figures