Chemistry contribution to stratospheric ozone depletion after the
unprecedented water rich Hunga Tonga eruption
Abstract
Following the Hunga Tonga–Hunga Ha’apai (HTHH) eruption in January
2022, stratospheric ozone depletion was observed in the Southern
Hemisphere mid-latitudes and Antarctica during the 2022 austral
wintertime and springtime. This eruption injected sulfur dioxide and
unprecedented amounts of water vapor into the stratosphere. This work
examines and quantifies the chemistry contribution of the volcanic
materials to the ozone depletion using chemistry-climate model
simulations with nudged meteorology. Simulated 2022 ozone and nitrogen
oxides (NOx) anomalies show a good agreement with satellite
observations. We find that chemistry only contributes up to 6% and 20%
ozone destruction at mid-latitudes wintertime and Antarctic springtime
respectively. The majority of the ozone depletion is attributed to the
internal variability and dynamical changes forced by the eruption. Both
the simulation and observations show a significant NOx reduction
associated with the HTHH aerosol plume, indicating the enhanced
dinitrogen pentoxide hydrolysis on sulfate aerosol.