[A-AS06] 大気圏（成層圏・対流圏）過程とその気候への影響

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

*藤原 正智¹、Martineau Patrick²、Wright Jonathon³、Abalos Marta⁴、Davis Sean⁵、Diallo Mohamadou⁶、Wang Xinyue⁷、秋吉 英治⁸、山下 陽介⁸、Minganti Daniele⁹ (1.北海道大学 大学院地球環境科学研究院、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)

キーワード：火山噴火、フンガトンガ、気候、再解析

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.