Emergence and cancellation of small-scale magnetic flux in a quiet region

Abstract

This paper studies the relationship between the development of granules and emergence (cancellation) of magnetic flux at small spatial scales (∼1″) in a quiet region taken with the spectro-polarimeter (SP) of the Solar Optical Telescope (SOT) aboard the Hinode satellite. By examining 6 granular cell events, we have uncovered that a granular structure develops in a regular shape with a size as large as 2–3″, while the granule is pure, i.e. no magnetic flux emerges in the granule during its development. However, a granular structure develops in an irregular shape while emerging flux accompanies the granular development. Magnetic flux cancellation takes place between new emerging flux and pre-existing one. The transverse magnetic field significantly appears at the place where a tiny bipole emerges and where two opposite polarities cancel each other, but only the transverse field of emerging bipole points from the positive element to the negative element. In some cases, violent Doppler blueshifts at the early emerging stage of the magnetic elements appear. We suggest that the excess of the blue-shifts in the inter-granular lanes are produced by the magnetic reconnection below the photosphere