Speaker
Description
At present, volcanic sulfate aerosols can lead to stratospheric ozone loss under the presence of anthropogenic chlorofluorocarbons (CFCs). Previous Chemistry Climate Model Initiative (CCMI-1) simulations showed that the Antarctic ozone hole is expected to be recovered by around 2060, although these simulations did not consider future volcanic eruptions. While atmospheric CFC levels have declined since the 1980s, future volcanic eruptions producing stratospheric volcanic sulfate aerosol may lead to a net increase in stratospheric column ozone. However, it remains uncertain whether future volcanic eruptions will lead to an earlier or a delayed recovery in Antarctic stratospheric ozone.
To investigate how future volcanic eruptions affect Antarctic ozone recovery, we generated 1000 stochastic future eruption scenarios based on an array of bipolar ice cores, satellite measurements and geological records spanning the last 11,500 years. We selected the low-end, median and high-end future stochastic scenarios based on ranked total SO2 mass and performed simulations from 2015 to 2100 using the UKESM-VPLUME plume-aerosol-chemistry-climate modelling framework with interactive sulfur chemistry and aerosol microphysics. Our model results show that future volcanic eruptions can delay the recovery of the Antarctic October-mean ozone mass deficit by 3 to 6 years, and October-mean ozone hole area (with an area threshold of 1 million km2) for up to 11 years. Our findings offer insights into the role of future volcanic eruptions in affecting Antarctic ozone recovery, as opposed to a previous modelling study suggesting no effects on polar ozone recovery. We also highlight the importance of incorporating interactive sulfur chemistry and aerosol microphysics in future modelling studies to assess the impact of volcanic eruptions on stratospheric ozone.
