Quantifying Properties of Photospheric Magnetic Cancellations in the Quiet Sun Internetwork

Abstract

Abstract We analyzed spectropolarimetric data from the Swedish 1 m Solar Telescope to investigate the physical properties of small-scale magnetic cancellations in the quiet Sun photosphere. Specifically, we looked at the full Stokes polarization profiles along the Fe i 557.6 nm and of the Fe i 630.1 nm lines measured by the CRisp Imaging SpectroPolarimeter to study the temporal evolution of the line-of-sight magnetic field during 42.5 minutes of quiet Sun evolution. From this magnetogram sequence, we visually identified 38 cancellation events. We then used the Yet Another Feature Tracking Algorithm to characterize the physical properties of these magnetic cancellations. We found on average 1.6 × 1016 Mx of magnetic flux canceled in each event with an average cancellation rate of 3.8 × 1014 Mx s−1. The derived canceled flux is associated with strong downflows, with an average speed of V LOS ≈ 1.1 km s−1. Our results show that the average lifetime of each event is 9.2 minutes with an average of 44.8% of initial magnetic flux being canceled. Our estimates of magnetic fluxes provide a lower limit since studied magnetic cancellation events have magnetic field values that are very close to the instrument noise level. We observed no horizontal magnetic fields at the cancellation sites and therefore cannot conclude whether the events are associated with structures that could cause magnetic reconnection.