Concurrence of a Kelvin-Helmholtz instability and Kármán vortex street in the Sun’s corona

Abstract

Context. Instabilities are crucial to understanding the mass transportation and energy transformation in the solar atmosphere. Observations of the concurrence among the Kelvin-Helmholtz instability (KHI) and Kármán vortex street (KVS) in conditions as extreme as the Sun’s corona have yet to be reported. Aims. We aim to find evidence of a concurrence between the KHI and KVS in the Sun’s corona. Methods. We analyzed high-resolution data from Extreme Ultraviolet Imager aboard Solar Orbiter and the Atmospheric Imaging Assembly aboard Solar Dynamics Observatory. Results. Thanks to the high temporal resolution of EUI data, in an interacting region between a jet and coronal plumes, we observed the development of ruffles and breakdown of blobs. The intrinsic parameters of this dynamic system suggest the possibility of both the KHI and KVS occurring in the corona. The observations also show that the coupling of the two instabilities has facilitated the formation of vortices, which may therefore have enhanced the transformation from kinetic energy to thermal energy, as well as mass mixing among systems across magnetic field lines in the Sun’s corona. Conclusions. The present study reports the very first EUI observations of a concurrence of the KHI and KVS and their coupling in the coronal conditions.

Connecting Solar Wind Velocity Spikes Measured by Solar Orbiter and Coronal Brightenings Observed by SDO

“…The detailed process of how jets and waves evolve into velocity spikes is not clear, but there are some proposed explanations. The reversing of magnetic field lines due to the shear-driven Kelvin-Helmholtz instability triggered by the propagation of jets (Wei et al 2023) is a potential source of switchbacks. In addition, the super-Parker spiral resulting from fast-speed jets overtaking the background solar wind (Schwadron & McComas 2021) may also cause the reversing of magnetic field lines.…”