High-resolution Observations of Physical Properties of Dynamic Fibrils around a Sunspot

Understanding the formation and evolution of dynamic fibrils (DFs) in active regions is essential for uncovering the physical processes operating in the highly structured and magnetized solar atmosphere. High-resolution chromospheric observations from the New Vacuum Solar Telescope (NVST) show DFs with periodic up-and-down motions. We carry out a statistical analysis of 176 DFs around a sunspot. The mean values of deceleration, maximum velocity, maximum length, and duration of the DFs are 120 ± 43 m s −2 , 15.9 ± 4.5 km s −1 , 1.13 ± 0.48 Mm, and 270 ± 63 s, respectively. Several pairs of parameters exhibit correlations, most notably a clear positive correlation between deceleration and maximum velocity. The consistency between the periodicities of DFs and running penumbral waves is first identified. We further find that DFs in regions with more vertical magnetic fields exhibit larger decelerations and shorter periods, whereas those in regions with more horizontal magnetic fields exhibit the opposite behavior. These results, together with the presence of running penumbral waves, support the interpretation that DFs are driven by slow magnetoacoustic waves. Furthermore, the multiwavelength signatures of DFs from the chromosphere to the corona imply a potential contribution to energy transport and heating in the solar atmosphere.