全球升温1.5℃和2℃下中国群发性高温事件与人口暴露度预估OA北大核心CSTPCD
Projection of the cluster high temperature events in China and population exposure under 1.5℃ and 2℃global warming
基于区域气候模式RegCM4 对 4 个全球气候模式的动力降尺度模拟数据及未来人口预估数据,预估了SSP2-RCP4.5 情景下全球升温1.5℃和2℃时,中国群发性高温事件(cluster high temperature events,CHTE)和CHTE人口暴露度的变化.结果表明:1.5℃和2℃升温阈值下,多模式集合(MME)预估CHTE年均频次相对于基准期分别增加31%和44%.不同强度事件中,严重CHTE事件的频次在1.5℃和2℃升温阈值下可分别增加约4.2 倍和6.8 倍.事件强度、持续时间、频次等指标趋向高值的发生概率更大.相对于 2℃,1.5℃温升阈值下CHTE年均频次、持续时间和累计强度在全国大范围呈降低趋势,且表现出明显的区域性差异,年均频次的降幅自北到南递增,新疆和长江以南地区持续时间年均减少 6 d以上(全国平均降幅为 0.2 d),我国中东部地区累计强度年均减少 20℃以上、新疆东部减少50℃以上(全国平均降幅为 0.6℃).此外,在 1.5℃和 2℃升温阈值下,MME预估CHTE影响人口的变化均呈现南增北减的空间分布,内蒙古地区略有减少,中东部地区普遍增加,全国总影响人口分别增加 1.4 倍和1.8 倍.高温事件对城市的影响人口增幅更大(分别增加2.9 倍和 3.8 倍),尤其是京津冀、长三角、珠三角、中原地区增幅最明显.全国的CHTE强度暴露度(分别增加2.2倍和5.2倍)和综合暴露度(分别增加1.2倍和1.8倍)呈明显增加趋势,特别是2℃升温阈值下城市的CHTE强度暴露度和综合暴露度的增幅分别高达10倍和4倍.
Based on four dynamical downscaling simulations by the regional climate model RegCM4(i.e.,CdR,EdR,HdR,and MdR)and population projection dataset under SSP2-RCP4.5,the characteristics of the cluster high temperature events(CHTE)in China under 1.5℃and 2℃global warming were projected.The multi-model ensemble(MME)mean projection indicates the annual frequency increases by 31%and 44%respectively at the 1.5℃and 2℃warmer worlds compared with the reference period,and the extreme CHTE increases by 4.2 and 6.8 times respectively.Besides,the proportion of the CHTE indicators such as the cumulative intensity,duration,frequency falling into'large value range'is expected to increase substantially.Compared with the CHTE under the 2℃warming,a significant decrease of CHTE metrics across the country is projected at the 1.5℃target,with remarkable regional differences.The reduction in frequency increases gradually from north to south.The duration decreases significantly by more than 6 days in Xinjiang and south of the Yangtze River(national averaged value is 0.2 days).The cumulative intensity decreases by more than 20℃in the east-central China,and by more than 50℃in the eastern part of Xinjiang(national averaged value is 0.6℃).In addition,under global warming of 1.5℃and 2℃,MME projects that a widespread increase can be clearly found in the population affected by the CHTEs,with a significant decrease in the Inner Mongolia region and an increase in the central and eastern regions.The national population affected by the CHTEs increases by 1.4 times and 1.8 times,respectively.The urban population affected by the CHTEs increases more significantly(by 2.9 times and 3.8 times respectively),particularly with the most significant increase in the Beijing-Tianjin-Hebei region,Yangtze River Delta,Pearl River Delta,and Central China.The intensity exposure shows a significant increasing trend(by 2.2 and 5.2 times respectively)under the 1.5℃and 2℃global warming,the same as the comprehensive exposure(by 1.2 and 1.8 times respectively).By contrast,the CHTE intensity exposure and comprehensive exposure on the urban population increase by up to 10 and 4 times respectively under the 2℃global warming.
程阳;韩振宇
中国气象局∙河南省农业气象保障与应用技术重点开放实验室,郑州 450003||新乡市气象防灾减灾重点实验室,新乡 453000||延津县气象局,新乡 453200中国气象局国家气候中心,北京 100081
群发性高温事件(CHTE)升温阈值区域气候模式人口暴露度模式集合预估
Cluster high temperature event(CHTE)Global warming targetRegional climate modelPopulation exposureEnsemble projection
《气候变化研究进展》 2024 (003)
278-290 / 13
广东省基础与应用基础研究重大项目(2020B0301030004);中国气象局气候变化专题项目(QBZ202404);中国气象局重点创新团队"气候变化检测与应对"(CMA2022ZD03);中国气象局∙河南省农业气象保障与应用技术重点实验室应用技术研究基金项目(KM202345);新乡市气象防灾减灾重点实验室技术研究项目(XX202205)
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