2011/02/07 by Yusuke Iida, Y. Iida, H. Hagenaar +5
Physics and Astronomy · #Astro and Planetary Science #FOS: Physical sciences #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.1102.1238
8 pages, 4 figures; 4th Hinode Science Meeting: Unsolved Problems and New Insights ASP Conference Series, Vol. 455 (2012)
openalex publication_date 2011/02/07 · arxiv created 2012/01/23 · arxiv updated 2015/03/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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). The quiet Sun magnetograms observed in the Na I line by Hinode/ SOT is used in this study. Investigated patches range from 1017Mx to 1019Mx. Emergence and cancellation are much less frequent than merging and splitting. The time scale for splitting is found to be ~33 minutes and is 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 only with a power-law index -0.33. These results suggest that 1) magnetic patches are fragmented by splitting, merging, and tiny cancellation; 2) flux is removed from the photosphere through tiny cancellations after these fragmentations.