The middle and lower Yangtze River basin(MLYRB)suffered persistent heavy rainfall in summer 2020,with nearly continuous rainfall for about six consecutive weeks.How the likelihood of persistent heavy rainfall resembling that which occurred over the MLYRB in summer 2020(hereafter 2020PHR-like event)would change under global warming is investigated.An index that reflects maximum accumulated precipitation during a consecutive five-week period in summer(Rx35day)is introduced.This accumulated precipitation index in summer 2020 is 60％stronger than the climatology,and a statistical analysis further shows that the 2020 event is a l-in-70-year event.The model projection results derived from the 50-member ensemble of CanESM2 and the multimodel ensemble(MME)of the CMIP5 and CMIP6 models show that the occurrence probability of the 2020PHR-like event will dramatically increase under global warming.Based on the Kolmogorov-Smirnoff test,one-third of the CMIP5 and CMIP6 models that have reasonable performance in reproducing the 2020PHR-like event in their historical simulations are selected for the future projection study.The CMIP5 and CMIP6 MME results show that the occurrence probability of the 2020PHR-like event under the present-day climate will be double under lower-emission scenarios(CMIP5 RCP4.5,CMIP6 SSP1-2.6,and SSP2-4.5)and 3-5 times greater under higher-emission scenarios(3.0 times for CMIP5 RCP8.5,2.9 times for CMIP6 SSP3-7.0,and 4.8 times for CMIP6 SSP5-8.5).The inter-model spread of the probability change is small,lending confidence to the projection results.The results provide a scientific reference for mitigation of and adaptation to future climate change.

Zi-An GE;Lin CHEN;Tim LI;Lu WANG

Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD),Nanjing University of Information Science and Technology,Nanjing 210044,China;International Pacific Research Center and Department of Atmospheric Sciences,School of Ocean and Earth Science and Technology,University of Hawaii at Manoa,Honolulu,Hawaii 96822,USA

大气科学进展（英文版）

[1]Zi-An GE;Lin CHEN;Tim LI;Lu WANG-.How Frequently Will the Persistent Heavy Rainfall over the Middle and Lower Yangtze River Basin in Summer 2020 Happen under Global Warming?)[J].大气科学进展（英文版）,2022(10):1673-1692

Happen,MLYRB,2020PHR,Rx35day,Smirnoff

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