[A-AS06] Atmospheric (Stratosphere-troposphere) Processes And their Role in Climate

[AAS06-03] Stratospheric responses to the Hunga Tonga-Hunga Ha’apai eruption in multiple reanalysis data sets

*Masatomo Fujiwara¹, Patrick Martineau², Jonathon Wright³, Marta Abalos⁴, Sean Davis⁵, Mohamadou Diallo⁶, Xinyue Wang⁷, Hideharu Akiyoshi⁸, Yousuke Yamashita⁸, Daniele Minganti⁹ (1.Faculty of Environmental Earth Science, Hokkaido University, 2.Japan Agency for Marine-Earth Science and Technology, 3.Tsinghua University, 4.Universidad Complutense de Madrid, 5.NOAA Chemical Sciences Laboratory, 6.Forschungszentrum Juelich GmbH, 7.University of Colorado Boulder, 8.National Institute for Environmental Studies, 9.Royal Belgian Institute for Space Aeronomy)

Keywords:volcanic eruption, Hunga Tonga, climate, reanalysis

Volcanic eruptions that directly inject materials into the stratosphere have significant impacts on climate and weather. Compared to other major eruptions, such as the the 1991 Mount Pinatubo and 1982 El Chichón eruptions, the eruption of Hunga Tonga-Hunga Ha’apai (20.5S) in January 2022 injected an unprecedented amount of water vapor into the stratosphere. In this work, we analyze zonal and monthly mean variables along with the major terms of the Transformed Eulerian Mean equations using four recent reanalyses, JRA-3Q, ERA5, MERRA-2, and JRA-55 up to the end of 2023 to investigate the impact of the water-rich eruption on temperature and meridional circulation in the global stratosphere. We use a multiple regression analysis method to isolate the volcanic signals from modes of climate variability such as the Quasi-Biennial Oscillation, and El Niño-Southern Oscillation, the solar cycle, and linear trends, as well as the seasonal cycle. In this presentation, we focus on the responses in June-July-August 2022, when we observed significant cooling responses in the Southern Hemisphere midlatitude stratosphere.