HDO and SO2 thermal mapping on Venus - VI. Anomalous SO2 behavior during late 2021 T. Encrenaz, T. K. Greathouse, R. Giles, T. Widemann, B. Bézard, M. Lefèvre and W. Shao A&A, 674 (2023) A199 Published online: 21 June 2023 DOI: 10.1051/0004-6361/202245831