DKIST unveils MHD-predicted sub-50 km photospheric vortices
Abstract
Solar vortices are rotating plasma structures that play a key role in the transport of energy and magnetic helicity from the photosphere to the chromosphere and corona. While numerical simulations predict the existence of small-scale photospheric vortices with diameters of $50−−100$ km, no direct observational evidence has been reported to date, primarily because of the limited spatial resolution of previous instrumentation. Here, we analyze high-resolution observations obtained with the 4-meter Daniel K. Inouye Solar Telescope (DKIST) at 416 nm, with a spatial resolution of 12.3 km. Using Fourier local correlation tracking and the swirling strength criterion (λci), we identify 201 vortex detections across a sequence of 143 reconstructed frames, spanning approximately 3.2 minutes, within a field of view of 4.92 × 4.13 Mm. The observations cover a photospheric plage region containing pore-like magnetic concentrations. The detected vortices have a median equivalent diameter of 38.6 km and a mean diameter of 39.5 ± 3.3 km. Virtually all detections are smaller than 50 km and therefore fall within the subgranular regime predicted by magnetohydrodynamic simulations but never previously observed. The median swirling period, τci=37.3 s, satisfies the τci<100 s criterion established by MURaM simulations. No statistically significant preference is found for prograde rotation (53.7\%) over retrograde rotation (46.3\%), consistent with the negligible influence of the Coriolis force at subgranular scales. These results demonstrate the unique capability of DKIST to resolve the population of photospheric convective vortices predicted by state-of-the-art magnetoconvection simulations, opening a new observational window into small-scale solar convective dynamics.
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BibTeX
@misc{dominguez2026dkist,
title = {{DKIST unveils MHD-predicted sub-50 km photospheric vortices}},
author = {S. Vargas Dominguez and O. A. Calvo Rebellon and J. S. Castellanos Duran and M. van Noort and F. Wöger and D. A. Rodriguez Torres and C. G. Bernal},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.30051},
eprint = {2609.30051},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.30051},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - DKIST unveils MHD-predicted sub-50 km photospheric vortices
AU - S. Vargas Dominguez
AU - O. A. Calvo Rebellon
AU - J. S. Castellanos Duran
AU - M. van Noort
AU - F. Wöger
AU - D. A. Rodriguez Torres
AU - C. G. Bernal
PY - 2026
DA - 2026/09/24
PB - arXiv
DO - 10.48550/arxiv.2609.30051
UR - https://arxiv.org/abs/2609.30051
AB - Solar vortices are rotating plasma structures that play a key role in the transport of energy and magnetic helicity from the photosphere to the chromosphere and corona. While numerical simulations predict the existence of small-scale photospheric vortices with diameters of $50−−100$ km, no direct observational evidence has been reported to date, primarily because of the limited spatial resolution of previous instrumentation. Here, we analyze high-resolution observations obtained with the 4-meter Daniel K. Inouye Solar Telescope (DKIST) at 416 nm, with a spatial resolution of 12.3 km. Using Fourier local correlation tracking and the swirling strength criterion (λ_ci), we identify 201 vortex detections across a sequence of 143 reconstructed frames, spanning approximately 3.2 minutes, within a field of view of 4.92 × 4.13 Mm. The observations cover a photospheric plage region containing pore-like magnetic concentrations. The detected vortices have a median equivalent diameter of 38.6 km and a mean diameter of 39.5 ± 3.3 km. Virtually all detections are smaller than 50 km and therefore fall within the subgranular regime predicted by magnetohydrodynamic simulations but never previously observed. The median swirling period, τ_ci=37.3 s, satisfies the τ_ci<100 s criterion established by MURaM simulations. No statistically significant preference is found for prograde rotation (53.7\%) over retrograde rotation (46.3\%), consistent with the negligible influence of the Coriolis force at subgranular scales. These results demonstrate the unique capability of DKIST to resolve the population of photospheric convective vortices predicted by state-of-the-art magnetoconvection simulations, opening a new observational window into small-scale solar convective dynamics.
ER -