The Impact of 2020 Hunga Tonga-Hunga Ha’apai (HTHH) Eruption on the Stratospheric Circulation and Climate

The Hunga Tonga-Hunga Ha’apai (HTHH) volcanic eruption was one of the most explosive eruptions observed in recent decades. The HTHH eruption injected a substantial amount of water vapor (>100 Tg) and a moderate amount of sulfur dioxide (~0.4 Tg) into the stratosphere. Both satellite observations in 2022 and subsequent chemistry-climate model simulations forced by realistic HTHH perturbations reveal large-scale cooling and a substantial ozone reduction in the stratosphere following the HTHH eruption. This study further investigates the detailed role of anomalies in water vapor, ozone, and sulfate aerosol concentration on the simulated climate response to the HTHH volcanic forcing in 2022 based on the Specified Chemistry version of Whole Atmosphere Community Climate Model (WACCM) simulations. The results will help to identify how each perturbation from the HTHH eruption (water vapor, ozone, and aerosol) influences radiative balances, stratospheric temperatures, and circulation.