Five-minute oscillations of photospheric and chromospheric swirls

Abstract

Context. Swirls are ubiquitous in the solar atmosphere. They are thought to be related to the excitation of different modes of magnetohydrodynamic waves and pulses, as well as spicules. However, statistical studies of their collective behaviour are rare. Aims. We aim to study the collective as well as the individual behaviour of photospheric and chromospheric swirls detected by the automated swirl detection algorithm (ASDA) from observations obtained by the Swedish 1-m Solar Telescope and the Hinode satellite. Methods. We performed a detailed analysis of six different parameters of photospheric and chromospheric swirls with the wavelet analysis. Two clusters with periods with significant wavelet power, one from 3 − 8 min and the other from 10 − 14 min, were found. The former coincides with the dominant period of the global p-mode spectrum. The wavelet and fast Fourier transform analysis of example swirls also revealed similar periods. Results. These results suggest that global p-modes might be important in triggering photospheric and thus chromospheric swirls. A novel scenario of global p-modes providing energy and mass fluxes to the upper solar atmosphere via generating swirls, Alfvén pulses, and spicules is then proposed.