Decadal disruption of the QBO by tropical volcanic supereruptions

It emitted enormous amounts of sulfur, chlorine, and bromine, with multi-decadal consequences for the global climate and environment. Here, we simulate the impact of a Los Chocoyos-like eruption on the quasi-biennial oscillation (QBO), an oscillation of zonal winds in the tropical stratosphere, with a comprehensive aerosol chemistry Earth System Model.

We find a similar to 10-year disruption of the QBO starting 4 months post eruption, with anomalous easterly winds lasting similar to 5 years, followed by westerlies, before returning to QBO conditions with a slightly prolonged periodicity. Volcanic aerosol heating and ozone depletion cooling leads to the QBO disruption and anomalous wind regimes through radiative changes and wave-mean flow interactions. Different model ensembles, volcanic forcing scenarios and results of a second model back up the robustness of our results.