Expulsion of Counter Evershed Flows from Sunspot Penumbrae

Abstract In addition to the Evershed flow directed from umbra toward outer boundary of a sunspot, under special circumstances counter (CEF) in opposite direction also occurs. We aim characterize proper motions and evolution three CEFs observed by Solar Optical Telescope on board Japanese Hinode spacecraft Helioseismic Magnetic Imager Dynamics Observatory. use state-of-the-art inversions radiative-transfer equation polarized light applied spectropolarimetric observations Fe i line pair around 630 nm. The appeared within penumbra. Two CEF structures, as part their decay process, were found move radially outwards through penumbra parallel penumbral filaments with speeds, deduced motions, ranging between 65 117 m s −1 . these two cases, new spot moat main sunspot after reached Meanwhile, moved away umbra, magnetic field strengths decreased. expulsion seems be related normal flow. third dragged rotation satellite spot. Chromospheric brightenings associated CEFs, those that umbra–penumbra showed enhanced chromospheric activity. for which line-of-sight velocity maps available during formation phase, appear intrusions into They may flux emergence.