Climate change and anthropogenic activities have driven significant terrestrial water storage changes(TWSC)in the Three Rivers Source Region(TRSR),exerting profound impacts on freshwater availability across China and ...Climate change and anthropogenic activities have driven significant terrestrial water storage changes(TWSC)in the Three Rivers Source Region(TRSR),exerting profound impacts on freshwater availability across China and broader Asia.However,long-term TWSC characterization remains challenging due to limited observational data in this alpine region.Here,we integrate GRACE observations(2002-2020),ERA5-Land reanalysis,and GLDAS data to reconstruct TWSC using two methods:(1)the water balance method(PER)and(2)the component summation method(SS),applied to three input datasets(ERA5-Land,GLDAS,and their average,GLER).Comparative analysis reveals that the SS method applied to GL-ER yields the highest consistency with GRACE-derived TWSC.Using this optimal approach,we extend the analysis to 1951~2020,uncovering spatiotemporal TWSC patterns.Although annual TWSC trends appear negligible due to strong seasonality,we introduce the intra-year TWSC fluctuation(TWSCF)index to quantify cumulative variability.A significant(p<0.05)transition occurred in 1980,with TWSCF shifting from a declining trend(-0.39 mm/yr)to an increasing trend(0.56 mm/yr),primarily driven by soil moisture changes.However,Hurst exponent analysis suggests this upward trend may not persist.Drought and vegetation assessments indicate concurrent wetting and greening in the TRSR.TWSC correlates strongly with meteorological drought,acting as a reliable drought indicator while its linkage with vegetation dynamics suggests a potential contribution to greening.Our findings provide a robust framework for understanding long-term TWSC evolution and its hydrological-ecological interactions under climate change.展开更多
One recent study by using instrumental records suggested the correlation between East Asian surface air temperatures(EATs)and the Atlantic Multidecadal Oscillation(AMO)reaches the maximum when the former leads the lat...One recent study by using instrumental records suggested the correlation between East Asian surface air temperatures(EATs)and the Atlantic Multidecadal Oscillation(AMO)reaches the maximum when the former leads the latter by 5–7 years.This seems to disagree with a previous well-realized point that the AMO modulates the decadal variation of EATs,since the atmosphere responds swiftly to sea surface temperature anomalies(SSTA)if therein.It implies that the AMO-EATs correlation should reach the maximum when they are simultaneous or the AMO leads EATs slightly,rather than that the EATs lead the AMO.Thus,this poses an issue about the reality of the newly found lead-lag correlation.Because the instrumental record in the natural climate system may be contaminated by human activities,the EATs-AMO lead-lag correlation derived from the instrumental records may not be a realistic connection of the natural climate system.Thus,whether the connection also exists in the proxies prior to the industrial is essential to answer the issue.In this study the EATs-AMO lead-lag connection is analyzed by using the reconstructed data in the last 500 years,together with the control experimental data with the prescribed pre-industrial forcing in a multiple of coupled climate system models,which attend the international CMIP5 program.The results suggest that the connection,the EATs lead the AMO,also exists in the period from the Little Ice Age(LIA)to the industrial,1500–1860AD.Therefore,the connection may be realistic in the natural climate system.The mechanisms for the connection are then discussed briefly.The results from this paper provide some insights into the connection of the AMO with East Asian climate.展开更多
基金funded by the Postdoctoral Research Startup Foundation of University of Jinan(Grant No.100389917).
文摘Climate change and anthropogenic activities have driven significant terrestrial water storage changes(TWSC)in the Three Rivers Source Region(TRSR),exerting profound impacts on freshwater availability across China and broader Asia.However,long-term TWSC characterization remains challenging due to limited observational data in this alpine region.Here,we integrate GRACE observations(2002-2020),ERA5-Land reanalysis,and GLDAS data to reconstruct TWSC using two methods:(1)the water balance method(PER)and(2)the component summation method(SS),applied to three input datasets(ERA5-Land,GLDAS,and their average,GLER).Comparative analysis reveals that the SS method applied to GL-ER yields the highest consistency with GRACE-derived TWSC.Using this optimal approach,we extend the analysis to 1951~2020,uncovering spatiotemporal TWSC patterns.Although annual TWSC trends appear negligible due to strong seasonality,we introduce the intra-year TWSC fluctuation(TWSCF)index to quantify cumulative variability.A significant(p<0.05)transition occurred in 1980,with TWSCF shifting from a declining trend(-0.39 mm/yr)to an increasing trend(0.56 mm/yr),primarily driven by soil moisture changes.However,Hurst exponent analysis suggests this upward trend may not persist.Drought and vegetation assessments indicate concurrent wetting and greening in the TRSR.TWSC correlates strongly with meteorological drought,acting as a reliable drought indicator while its linkage with vegetation dynamics suggests a potential contribution to greening.Our findings provide a robust framework for understanding long-term TWSC evolution and its hydrological-ecological interactions under climate change.
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.41375085,41421004)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA05090406)
文摘One recent study by using instrumental records suggested the correlation between East Asian surface air temperatures(EATs)and the Atlantic Multidecadal Oscillation(AMO)reaches the maximum when the former leads the latter by 5–7 years.This seems to disagree with a previous well-realized point that the AMO modulates the decadal variation of EATs,since the atmosphere responds swiftly to sea surface temperature anomalies(SSTA)if therein.It implies that the AMO-EATs correlation should reach the maximum when they are simultaneous or the AMO leads EATs slightly,rather than that the EATs lead the AMO.Thus,this poses an issue about the reality of the newly found lead-lag correlation.Because the instrumental record in the natural climate system may be contaminated by human activities,the EATs-AMO lead-lag correlation derived from the instrumental records may not be a realistic connection of the natural climate system.Thus,whether the connection also exists in the proxies prior to the industrial is essential to answer the issue.In this study the EATs-AMO lead-lag connection is analyzed by using the reconstructed data in the last 500 years,together with the control experimental data with the prescribed pre-industrial forcing in a multiple of coupled climate system models,which attend the international CMIP5 program.The results suggest that the connection,the EATs lead the AMO,also exists in the period from the Little Ice Age(LIA)to the industrial,1500–1860AD.Therefore,the connection may be realistic in the natural climate system.The mechanisms for the connection are then discussed briefly.The results from this paper provide some insights into the connection of the AMO with East Asian climate.
