Changes in Tropical Cyclone Activity Affecting East Asia over the Western North Pacific under Four Global Warming Targets of 1.5-4℃

WU Jie; SHI Ying

doi:10.16032/j.issn.1004-4965.2025.031

Abstract：Tropical cyclones(TCs)generated in the western North Pacific(WNP)pose significant threats to China's coastal regions each year.Thus,projecting changes in TC activity over the WNP under different global warming scenarios holds substantial importance.Utilizing four CMIP5 global climate models(EC-EARTH,HadGEM2-ES,MPI-ESM-MR,NorESM1-M)drive to the regional climate model RegCM4,simulations of East Asian climate change were performed.Projections of TC activity changes over the WNP under global warming targets of 1.5℃,2℃,3℃,and 4℃were carried out.Results demonstrate that with increasing global mean temperature,the spatial distribution of areas with heightened TC genesis and occurrence frequency progressively enlarges.TC tracks tend to move poleward and eastward.Relative to the 1986-2005 baseline,under all four global warming scenarios,the monthly mean TC number in April and June-September is projected to rise.The largest increases in TC frequency are expected in June,August,and September(April and July)under the 3℃(4℃)warming target,with increments of 0.79,0.92,and 1.25(0.44 and 1.35),respectively.In terms of duration,TC intensity,and minimum sea level pressure,their spatial distributions exhibit similarity across the present day and the four global warming scenarios.Projections indicate that under the 4℃global warming target,the maximum number of strong TCs(typhoons and intense typhoons,defined by minimum sea level pressure<980 hPa)will surpass 1.48.Projections suggest that the most substantial increases in TC landfall frequency over China(Japan)will be 0.98(0.75)under the 3℃(2℃)global warming target.Meanwhile,landfall frequencies over South Korea and North Korea are anticipated to remain relatively stable.