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Recent progress in instrumentation enables solar observations with highresolution simultaneously in the spatial, temporal, and spectral domains. Weuse such high-resolution observations to study small-scale structures anddynamics in the chromosphere of the quiet Sun. We analyze time series ofspectral scans through the Ca II 854.2nm spectral line obtained with the CRISPinstrument at the Swedish 1-m Solar Telescope. The targets are quiet Sunregions inside coronal holes close to disc-centre. The line core maps exhibitrelatively few fibrils compared to what is normally observed in quiet Sunregions outside coronal holes. The time series show a chaotic and dynamic scenethat includes spatially confined "swirl" events. These events feature dark andbright rotating patches, which can consist of arcs, spiral arms, rings or ringfragments. The width of the fragments typically appears to be on the order ofonly 0.2", which is close to the effective spatial resolution. They exhibitDoppler shifts of -2 to -4 km/s but sometimes up to -7 km/s, indicating fastupflows. The diameter of a swirl is usually of the order of 2". At the locationof these swirls, the line wing and wide-band maps show close groups ofphotospheric bright points that move with respect to each other. A likelyexplanation is that the relative motion of the bright points twists theassociated magnetic field in the chromosphere above. Plasma or propagatingwaves may then spiral upwards guided by the magnetic flux structure, therebyproducing the observed intensity signature of Doppler-shifted ring fragments.

Small-scale swirl events in the quiet Sun chromosphere