Elevated atmospheric CO2 drove an increase in tropical cyclone intensity during the early Toarcian hyperthermal

Qing Yan; Xiang Li; David B Kemp; Jiaqi Guo; Zhongshi Zhang; Yongyun Hu

doi:10.1073/pnas.2301018120

Elevated atmospheric CO₂ drove an increase in tropical cyclone intensity during the early Toarcian hyperthermal

Proc Natl Acad Sci U S A. 2023 Jul 18;120(29):e2301018120. doi: 10.1073/pnas.2301018120. Epub 2023 Jul 10.

Authors

Qing Yan^{1

2}, Xiang Li³, David B Kemp⁴, Jiaqi Guo³, Zhongshi Zhang⁵, Yongyun Hu³

Affiliations

¹ Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
² Key Laboratory of Meteorological Disaster/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China.
³ Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China.
⁴ State Key Laboratory of Biogeology and Environmental Geology and Hubei Key Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan 430074 China.
⁵ Department of Atmospheric Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.

Abstract

The occurrence of sedimentary storm deposits around the Tethys Ocean during the early Toarcian hyperthermal (~183 Ma) suggests that intensified tropical cyclone (TC) activity occurred in response to CO₂ rise and marked warming. However, this hypothesized linkage between extreme warmth and storm activity remains untested, and the spatial pattern of any changes in TCs is unclear. Here, model results show that there were two potential storm genesis centers over Tethys during the early Toarcian hyperthermal located around the northwestern and southeastern Tethys. The empirically determined doubling of CO₂ concentration that accompanied the early Toarcian hyperthermal (~500 to ~1,000 ppmv) leads to increased probability of stronger storms over Tethys, in tandem with more favorable conditions for coastal erosion. These results match well with the geological occurrence of storm deposits during the early Toarcian hyperthermal and confirm that increased TC intensity would have accompanied global warming.

Keywords: early Toarcian hyperthermal; paleoclimate modeling; tropical cyclone.

Abstract

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