2008/07/28 by Masahito Kubo, M. Kubo, B. W. Lites +4 · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/592064
16 pages, 7 figures, Accepted for publication in ApJ
arxiv created 2008/07/28 · openalex publication_date 2008/10/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We estimate the temporal change of magnetic flux normal to the solar surface in a decaying active region by using a time series of the spatial distribution of vector magnetic fields in the photosphere. The vector magnetic fields are derived from full spectropolarimetric measurements with the Solar Optical Telescope aboard Hinode . We compare a magnetic flux loss rate to a flux transport rate in a decaying sunspot and its surrounding moat region. The amount of magnetic flux that decreases in the sunspot and moat region is very similar to magnetic flux transported to the outer boundary of the moat region. The flux loss rates [( dF / dt ) loss ] of magnetic elements with positive and negative polarities balance each other around the outer boundary of the moat region. These results suggest that most of the magnetic flux in the sunspot is transported to the outer boundary of the moat region as moving magnetic features, and then removed from the photosphere by flux cancellation around the outer boundary of the moat region.