摘要
降水是地球气候系统中关键的组成部分,其变化对区域水资源安全、农业生产和生态系统具有深远影响。本文利用地球系统模式1.2.1版(Community Earth System Model,CESM1)和全球降水气候学计划(Global Precipitation Climatology Project,GPCP)观测资料,定量分析了过去40 a(1980—2019年)全球人为气溶胶排放的量级与空间分布变化对中国降水的影响。通过对比不同敏感性试验发现,1980—2019年全球气溶胶变化导致中国南部年均降水量减少,其主要受人为排放空间再分布主导,而排放总量变化的贡献相对较小。1980—2019年,全球人为气溶胶排放热点从高纬度欧美地区向低纬度南亚和东亚转移。中国南方地区PM 2.5柱浓度显著增加,导致云滴数浓度上升、云滴半径减小,降水效率降低。结果表明,全球人为气溶胶排放的空间分布变化在过去40 a中主导了中国南部降水的持续减少,凸显了在评估气溶胶气候效应时需同时考虑排放的地理格局及其区域气候反馈。
Precipitation is a fundamental component of the Earth's climate system,and its variability strongly influences regional water resources,agricultural productivity,and ecosystem health.In this study,we used the Community Earth System Model(CESM1)together with Global Precipitation Climatology Project(GPCP)observations to quantitatively assess how changes in both the magnitude and spatial distribution of global anthropogenic aerosol emissions have affected precipitation over China during the past four decades(1980—2019).Sensitivity experiments demonstrate that global aerosol changes have contributed to a decrease in annual-mean precipitation over southern China,with the dominant driver being the spatial redistribution of emissions rather than changes in their total magnitude.From 1980 to 2019,global anthropogenic aerosol emission hotspots shifted from high latitudes(Europe and North America)toward lower-latitude regions in South Asia and East Asia.This shift resulted in a pronounced increase in PM 2.5 column burden over southern China,which in turn enhanced cloud droplet number concentrations,reduced cloud droplet radius,and weakened precipitation efficiency.These findings indicate that changes in the spatial distribution of anthropogenic aerosol emissions have played a central role in the persistent decline in precipitation over southern China during the past four decades.The results highlight the importance of considering both the geographic pattern of emissions and their associated regional climate feedbacks when evaluating aerosol-climate interactions.
作者
杨洋
李姝歆
廖宏
YANG Yang;LI Shuxin;LIAO Hong(St ate Key Laboratory of Climate System Prediction and Risk Management(CPRM)/School of Environmental Science and Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China)
出处
《大气科学学报》
2026年第1期147-155,共9页
Transactions of Atmospheric Sciences
基金
国家自然科学基金项目(42521006,42475032)。
关键词
气溶胶
人为排放
降水变化
地球系统模式
气候反馈
aerosols
anthropogenic emissions
precipitation change
Earth System Model
climate feedback
