The eruption of the submarine Hunga volcano in January 2022 was associated with a powerful blast that injected volcanic material to altitudes up to 58 km. From a combination of various types of satellite and ground-based observations supported by transport modeling, we show evidence for an unprecedented increase in the global stratospheric water mass by 13% as compared to climatological levels, and a 5-fold increase of stratospheric aerosol load, the highest in the last three decades. Owing to the extreme injection altitude, the volcanic plume has circumnavigated the Earth in only one week and dispersed nearly pole-to-pole in three months. The unique nature and magnitude of the global stratospheric perturbation by the Hunga eruption ranks it among the most remarkable climatic events in the modern observation era, with a range of potential persistent repercussions for stratospheric composition and climate.

The Quasi-Biennial Oscillation (QBO) is a major mode of climate variability with periodically descending westerly and easterly winds in the tropical stratosphere, modulating transport and distributions of key greenhouse gases such as water vapor and ozone. In 2016 and 2020, anomalous QBO easterlies disrupted the QBO’s 28–month period previously observed. Here, we quantify the impact of these QBO disruptions on lower stratospheric circulation, and water vapour and ozone using reanalyses and satellite observations, respectively. Both constituents decrease globally from early spring to late autumn during 2016, while they only weakly decrease during 2020. These dissimilarities result from differences in upwelling and cold-point tropopause temperatures caused by anomalous planetary and gravity wave forcing. Our results highlight the need for a better understanding of the causes of QBO disruptions, their interplay with other modes of climate variability, and their impacts on water vapor and ozone in the face of a changing climate.