大气科学学报2025，Vol.48Issue(4)：556-563,8.DOI:10.13878/j.cnki.dqkxxb.20241015001
欧亚夏季非均匀增暖的成因研究及展望
Summer non-uniform temperature variations over Eurasia:mechanisms and implications
摘要
Abstract
Surface temperatures have risen in decades,with an increasing frequency of summer heat waves over most land areas,particularly across Eurasia.This rapid warming and the intensification of extreme temperatures have significant environmental,economic,and societal impacts,making it crucial to understand the underlying causes.Observational data indicate that since the mid-1990s,summer warming has been remarkably amplified over Europe and East Asia,revealing non-uniform decadal warming rates across Eurasia.This heterogenous warming pattern may result from internal multidecadal variability—such as the Atlantic Multidecadal Oscillation(AMO)—as well as changes in anthropogenic greenhouse gases(GHGs)and aerosols.However,the relative contributions of these factors to Eurasia's summer warming patterns remain unclear.A more precise quantification of the roles played by the AMO,decadal variations in aerosol,and other external forcing mechanisms could im-prove our understanding of recent non-uniform warming trends.Results indicate that GHG-induced surface air temperature(SAT)increases are most pronounced over the driest regions of Eurasia and North Africa,though decadal variations in GHG-induced SAT changes are minimal.To isolate external forcing effects unrelated to the steady rise in GHGs,this study removes the GHG-induced SAT component from observations and applies an em-pirical orthogonal function analysis to the residuals(referred to as GHG-detrended SAT),identifying the dominant spatial and temporal characteristics of Eurasian SAT variability.The GHG-detrended SAT exhibits strong multidecadal fluctuations,with negative anomalies from the 1960s to the mid-1990s and positive anomalies during the 1950s,early 1960s and post-1990s.Between 1984 and 2014,significant warming occurred over Europe-West Asia and Central East Asia,whereas 1953-1984 saw widespread cooling.Central Asia,however,experienced only weak out-of-phase variations.The estimated internal variability component reveals a similar tri-pole pattern,with a pronounced negative center over Central Asia,closely correlated with GHG-detrended SAT variations.These findings confirm that the AMO is the dominant driver of multidecadal SAT variability over Eura-sia.Meanwhile,the estimated externally forced component exhibits comparable multidecadal fluctuations but with consistent spatial coefficients across Eurasia.Over the period 1950-2014,externally forced changes accounted for approximately 55％of the GHG-detrended multidecadal SAT variations over Europe-West Asia and～51％over East Asia,with the remainder attributed to internal variability.These results suggest that,contrary to previous as-sumptions,more than half of Eurasia's multidecadal SAT variability since 1950 has been externally forced rather than predominantly driven by internal variability.Furthermore,the primary driver of externally forced non-uniform multidecadal SAT variations is identified as anthropogenic aerosols.This study demonstrates that both external forcing and internally driven variability originating from the Atlantic Ocean have contributed to Eurasia's multid-ecadal SAT variations since 1950.Looking ahead,continued reductions in aerosol concentrations,the likely persist-ence of the AMO in its positive phase,and ongoing increases in GHGs are expected to future intensify warm-sea-son temperatures across Europe-West Asia and East Asia in the coming decade.关键词
欧亚非均匀增暖/外强迫/气候系统内部变率/大西洋多年代际变化/丝绸之路遥相关Key words
Eurasian non-uniform warming/external forcing/internal variability of the climate system/Atlantic multidecadal variability/the Silk Road Pattern引用本文复制引用
华文剑,王希,胡宇涵,冯慧婷,周璐..欧亚夏季非均匀增暖的成因研究及展望[J].大气科学学报,2025,48(4):556-563,8.基金项目
国家重点研发计划项目(2022YFF0801601) （2022YFF0801601）
国家自然科学基金项目(42075022) （42075022）
