[A-CG31] Climate Variability and Predictability on Subseasonal to Centennial Timescales

[ACG31-P09] Robust future projections of global spatial distribution of major tropical cyclones and sea level pressure gradients

*村上 裕之¹、Cooke William¹、水田 亮²、遠藤 洋和²、吉田 康平²、Wang Shuai³、Hsu Pang-Chi⁴ (1.Geophysical Fluid Dynamics Laboratory、2.気象研究所、3.Univeristy of Delaware、4.Nanjing University of Information Science and Technology)

キーワード：地球温暖化、メジャーハリケーン、気候モデリング、海面気圧勾配、山火事

Despite the profound societal impacts of intense tropical cyclones (TCs), prediction of future changes in their regional occurrence remains challenging owing to climate model limitations and to the infrequent occurrence of such TCs. This study revealed robust projected changes in the frequency of occurrence of major TCs (i.e., maximum sustained wind speed: >50 m s^-1) on the regional scale. Two independent high-resolution climate models robustly projected the spatial patterns of change in major TC occurrence—increase in the central Pacific and reduction in the Southern Hemisphere—attributable to anthropogenically induced climate change. Furthermore, these models projected robust increase in events of abrupt rise in the meridional sea-level pressure gradient, especially in the central Pacific, indicating enhanced risk of storm hazards such as the 2023 wildfire on Maui Island caused by Hurricane Dora. Future changes in the frequency of abrupt rise in the sea level pressure gradient are strongly related to projected changes in the regional frequency of occurrence of major TCs. This research highlights the possibility of future heterogeneous variation in the global occurrence of major TC disasters depending on region.