Stratospheric Impacts of the Hunga-Tonga Aerosol Perturbation

The Hunga-Tonga eruption in January 2022 injected water vapor and sulfur dioxide (SO₂) into the mid-stratosphere, with the SO₂ rapidly converted into sulfate aerosol particles. The corresponding increase in aerosol surface area density (SAD) and optical depth (AOD) impacted the chemistry and radiative balance of the stratosphere in the months following the eruption. In this study, we use the Ozone Mapping and Profile Suite (OMPS) limb Profiler (LP) measurements to derive profiles of stratospheric SAD and AOD anomalies as a function of latitude for January 2022 to November 2023. These quantities are input in a 2-D (latitude-altitude) model to examine the impacts on stratospheric ozone and temperature. The anomalous SAD altered stratospheric chemistry, reducing total column ozone throughout the Southern hemisphere (SH) starting in May 2022. In 2022, maximum total ozone decreases of 5-6 DU occurred at SH mid-latitudes in October-November. The anomalous AOD caused warming of the lower stratosphere, with maximum temperature increases of 0.5K in the SH subtropics in May-July 2022. These results will be compared with model simulations that include the Hunga-Tonga water vapor anomaly and will include the 2023 Antarctic ozone hole time period. Comparisons with NASA MERRA-2 assimilated temperatures and Aura microwave limb sounder ozone measurements will also be made.