First Statistical Analysis of Photospheric Intensity Vortices with DKIST/VBI

Abstract Using high-resolution ground-based Fe I (630.2 nm) data from SST/CRISP and TiO (705.8 nm) data from DKIST/VBI-Red in separate observing runs, we analyze photospheric intensity vortices. We identify these vortices using the Γ functions, deriving the velocity fields from Fourier local correlation tracking (FLCT) plane-of-sky flow vectors, and report their statistics. We perform the closest possible statistical comparison between instruments through the choice of FLCT kernel size σ and the Γ function search range S and find excellent agreement in macroscopic properties, such as diameters and lifetimes. We also study the role of S in the extracted statistics and the relationships between kinematic properties, finding no strong correlation between area and lifetime. We also find that VBI-Red is able to allow the meaningful extraction of the internal velocity structure of photospheric intensity vortices for the first time, via FLCT and the Γ functions, and present examples of nine case studies. In addition, we also find that VBI-Red is capable of detecting vortices below the resolution limit of SST after applying the same detection and tracking methodology to both datasets. We conclude that DKIST/VBI-Red enables the investigation of photospheric intensity vortices at previously unresolved spatial scales, with the ability to provide important new insights into the underpinning physics driving these structures.