The first ground-level enhancement of solar cycle 25 on 28 October 2021
A. Papaioannou, A. Kouloumvakos, A. Mishev, R. Vainio, I. Usoskin, K. Herbst, A. P. Rouillard, A. Anastasiadis, J. Gieseler, R. Wimmer-Schweingruber and P. Kühl
A&A, 660 (2022) L5
DOI: https://doi.org/10.1051/0004-6361/202142855
