High-resolution Observations of Dynamics of Superpenumbral Hα Fibrils

Abstract

Abstract We present high-resolution Hα observations of a small solar pore in NOAA active region 12661, using the 1.6 m Goode Solar Telescope equipped with high-order adaptive optics at Big Bear Solar Observatory. The observations reveal copious fine-scale chromospheric superpenumbral fibrils (with an average cross-sectional width of ∼0.″17 ± 0.″03), along with associated transit and intermittent flows with apparent speeds of 5–14 km s−1. Wavelet analysis and the spatio-temporal pattern of superpenumbral fibrils suggest that the observed flows along fibrils are not likely an oscillation/wave phenomenon. Based on our pseudo-Dopplergrams, we suggest that the observed flows may be a phenomenon similar to inverse Evershed flows in the chromosphere. The three-dimensional potential field model indicates that the pore and the surrounding fibrils are enclosed by fan-field lines forming a separatrix dome configuration. Such a magnetically confined configuration may help to maintain the steadfastness of the superpenumbral fibril dynamics.