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Title: PHOTOSPHERIC FLOW FIELD RELATED TO THE EVOLUTION OF THE SUN'S POLAR MAGNETIC PATCHES OBSERVED BY HINODE SOLAR OPTICAL TELESCOPE

We investigated the role of photospheric plasma motions in the formation and evolution of polar magnetic patches using time-sequence observations with high spatial resolution. The observations were obtained with the spectropolarimeter on board the Hinode satellite. From the statistical analysis using 75 magnetic patches, we found that they are surrounded by strong converging, supergranulation associated flows during their apparent lifetime and that the converging flow around the patch boundary is better observed in the Doppler velocity profile in the deeper photosphere. Based on our analysis, we suggest that the like-polarity magnetic fragments in the polar region are advected and clustered by photospheric converging flows, thereby resulting in the formation of polar magnetic patches. Our observations show that, in addition to direct cancellation, magnetic patches decay by fragmentation followed by unipolar disappearance or unipolar disappearance without fragmentation. It is possible that the magnetic patches of existing polarity fragment or diffuse away into smaller elements and eventually cancel out with opposite polarity fragments that reach the polar region around the solar cycle maximum. This could be one of the possible mechanisms by which the existing polarity decays during the reversal of the polar magnetic field.
Authors:
; ;  [1] ; ;  [2] ;  [3]
  1. Department of Astronomical Science, Graduate University for Advanced Studies (SOKENDAI), Mitaka, Tokyo 181-8588 (Japan)
  2. Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan)
  3. Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan)
Publication Date:
OSTI Identifier:
22364400
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 799; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; GRANULATION; LIFETIME; MAGNETIC FIELDS; PHOTOSPHERE; PLASMA; POLAR REGIONS; SATELLITES; SOLAR CYCLE; SOLAR GRANULATION; SOLAR SYSTEM EVOLUTION; SPATIAL RESOLUTION; SUN; TELESCOPES