The progress and advances of the detection and attribution of changes in the hydrological cycle in the IPCC Assessment Reports of WGI and WGII from 1990 to 2007 are reviewed. Accomplishment and endorsed by the joint E...The progress and advances of the detection and attribution of changes in the hydrological cycle in the IPCC Assessment Reports of WGI and WGII from 1990 to 2007 are reviewed. Accomplishment and endorsed by the joint Expert Meeting on Detection and Attribution in 2009, the Good Practice Guidance Paper （GPGP） for IPCC Lead Authors with its main content and characteristics are briefly introduced. Based on the review and the purpose of the GPGP, some characteristics on the detection and attribution of global warming and of changes in the hydrological cycle are presented.展开更多
Northeastern China has experienced a significant increase in summer compound hot and dry events(CHDEs),posing a threat to local agricultural production and sustainable development.This study investigates the detectabl...Northeastern China has experienced a significant increase in summer compound hot and dry events(CHDEs),posing a threat to local agricultural production and sustainable development.This study investigates the detectable anthropogenic signal in the long-term trend of CHDE and quantifies the contribution of different external forcings.A probability-based index(PI)is constructed through the joint probability distribution to measure the severity of CHDE,with lower values representing more severe cases.Response of CHDE to external forcing was assessed with simulations from the Coupled Model Intercomparison Project phase 6(CMIP6).The results show a significant increase in the severity of CHDE over northeastern China during the past decades.The trend of regional averaged PI is-0.28(90%confidence interval:-0.43 to-0.13)per 54 yr and it is well reproduced in the historical forcing simulations.The attribution method of optimal fingerprinting was firstly applied to a two-signal configuration with anthropogenic forcing and natural forcing;the anthropogenic impact was robustly detected and it explains most of the observed trend of PI.Similarly,three-signal analysis further demonstrated that the anthropogenic greenhouse gases dominantly contribute to the observed change,while the anthropogenic aerosol and natural forcing have almost no contribution to the observed changes.For a compound event concurrently exceeding the 95 th percentile of surface air temperature and precipitation reversal in the current period,its likelihood exhibits little change at 1.5℃global warming,but almost doubled at 2.0℃global warming.展开更多
The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risk...The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risks,including floods and droughts.Recent research associated with the implementation of the Global Monsoons Model Intercomparison Project under the umbrella of CMIP6 has advanced our understanding of its historical variability and driving mechanisms.Observational data reveal a 20th-century shift:increased rainfall pre-1950s,followed by aridification and partial recovery post-1980s,driven by both internal variability(e.g.,Atlantic Multidecadal Oscillation)and external forcings(greenhouse gases,aerosols),while ENSO drives interannual variability through ocean-atmosphere interactions.Future projections under greenhouse forcing suggest long-term monsoon intensification,though regional disparities and model uncertainties persist.Models indicate robust trends but struggle to quantify extremes,where thermodynamic effects(warming-induced moisture rise)uniformly boost heavy rainfall,while dynamical shifts(circulation changes)create spatial heterogeneity.Volcanic eruptions and proposed solar radiation modification(SRM)further complicate predictions:tropical eruptions suppress monsoons,whereas high-latitude events alter cross-equatorial flows,highlighting unresolved feedbacks.The emergent constraint approach is booming in terms of correcting future projections and reducing uncertainty with respect to the global monsoons.Critical challenges remain.Model biases and sparse 20th-century observational data hinder accurate attribution.The interplay between natural variability and anthropogenic forcings,along with nonlinear extreme precipitation risks under warming,demands deeper mechanistic insights.Additionally,SRM’s regional impacts and hemispheric monsoon interactions require systematic evaluation.Addressing these gaps necessitates enhanced observational networks,refined climate models,and interdisciplinary efforts to disentangle multiscale drivers,ultimately improving resilience strategies for monsoon-dependent regions.展开更多
Extreme weather events and their consequential impacts have been a key feature of the climate in recent years in many parts of the world,with many partly attributed to ongoing global-scale warming.The past year,2022,h...Extreme weather events and their consequential impacts have been a key feature of the climate in recent years in many parts of the world,with many partly attributed to ongoing global-scale warming.The past year,2022,has been no exception,with further records being broken.The year was marked by unprecedented heatwaves and droughts with highly unusual spatial extent,duration and intensity,with one measure indicating an aggregated and overall intensity of extreme heat events worldwide not seen since at least 1950.The extreme drought measured by surface soil moisture covered 47.3%of global land areas in 2022,which was the second most widespread year since 1980.Here,we examine notable events of the year in five major regions of the world:China’s Yangtze River region,western Europe,the western U.S.,the Horn of Africa and central South America.For each event,we review the potential roles of circulation,oceanic forcing(especially the“triple-dip”La Niña)and anthropogenic climate change,with an aim of understanding the extreme events in 2022 from a global perspective.This will serve as a reference for mechanism understanding,prediction and attribution of extreme events.展开更多
The year 2021 was recorded as the 6th warmest since 1880.In addition to large-scale warming,2021 will be remembered for its unprecedented climate extremes.Here,a review of selected high-impact climate extremes in 2021...The year 2021 was recorded as the 6th warmest since 1880.In addition to large-scale warming,2021 will be remembered for its unprecedented climate extremes.Here,a review of selected high-impact climate extremes in 2021,with a focus on China,along with an extension to extreme events in North America and Europe is presented.Nine extreme events that occurred in 2021 in China are highlighted,including a rapid transition from cold to warm extremes and sandstorms in spring,consecutive drought in South China and severe thunderstorms in eastern China in the first half of the year,extremely heavy rainfall over Henan Province and Hubei Province during summer,as well as heatwaves,persistent heavy rainfall,and a cold surge during fall.Potential links of extremes in China to four global-scale climate extremes and the underlying physical mechanisms are discussed here,providing insights to understand climate extremes from a global perspective.This serves as a reference for climate event attribution,process understanding,and high-resolution modeling of extreme events.展开更多
The frequent and rapid onset of flash drought poses a serious threat to agriculture and ecosystems.Detecting human influences on flash droughts and estimating their future risks under climate change have attracted gre...The frequent and rapid onset of flash drought poses a serious threat to agriculture and ecosystems.Detecting human influences on flash droughts and estimating their future risks under climate change have attracted great attention.Focusing on a record-breaking flash drought event in the southeastern coastal region of China in summer 2020,the authors found that the suppression of convective precipitation and high temperature caused by the persistent high geopotential height anomalies and land-atmosphere dry coupling were important reasons for the rapid onset and strong intensity of the flash drought.Event attribution analysis with the latest CMIP6 data showed that anthropogenic climate change has not only increased the likelihood of an onset speed and intensity like those of the 2020 flash drought event,by about 93%±20%and 18%±15%,respectively,but also increased the chance of their simultaneous occurrence,by about 86%±38%,according to their joint probability distribution.Under a business-as-usual future scenario(SSP2-4.5),the likelihood of such an onset speed,intensity,and their simultaneous occurrence will further increase,by 85%±33%,49%±8%,and 81%±48%,respectively,as compared with current climate conditions.This study highlights the importance of anthropogenic climate change for accelerating and intensifying flash drought in the southeastern coastal region of China.展开更多
While being successful in the detection and attribution of climate change,the optimal fingerprinting method(OFM)may have some limitations from a physics-and-dynamics-based viewpoint.Here,an analysis is made on the lin...While being successful in the detection and attribution of climate change,the optimal fingerprinting method(OFM)may have some limitations from a physics-and-dynamics-based viewpoint.Here,an analysis is made on the linearity,noninteraction,and stationary-variability assumptions adopted by OFM.It is suggested that furthering OFM needs a viewpoint beyond statistical science,and the method should be combined with theoretical tools in the dynamics and physics of the Earth system,so as to be applied for the detection and attribution of nonlinear climate change including tipping elements within the Earth system.展开更多
This paper reviews recent progress in climate change attribution studies. The focus is on the attribution of ob-served long-term changes in surface temperature, precipitation, circulation, and extremes, as well as tha...This paper reviews recent progress in climate change attribution studies. The focus is on the attribution of ob-served long-term changes in surface temperature, precipitation, circulation, and extremes, as well as that of specific extreme weather and climate events. Based on new methods and better models and observations, the latest studies ftLrther verify the conclusions on climate change attribution in the IPCC AR5, and enrich the evidence for anthropo-genie influences on weather and climate variables and extremes. The uncertainty of global temperature change attrib- utable to anthropogenic forcings lies in the considerable uncertainty of estimated total radiative forcing due to aero- sols, while the uncertainty of precipitation change attribution arises from the limitations of observation and model simulations along with influences from large internal variability. In terms of extreme weather and climate events, it is clear that attribution studies have provided important new insights into the changes in the intensity or frequency of some of these events caused by anthropogenic climate change. The framing of the research question, the methods se- lected, and the model and statistical methods used all have influences on the results and conclusions drawn in an event attribution study. Overall, attribution studies in China remain inadequate because of limited research focus and the complexity of the monsoon climate in East Asia. Attribution research in China has focused mainly on changes or events related to temperature, such as the attribution of changes in mean and extreme temperature and individual heat wave events. Some progress has also been made regarding the pattern of changes in precipitation and individual ex-treme rainfall events in China. Nonetheless, gaps remain with respect to the attribution of changes in extreme precip-itation, circulation, and drought, as well as to the event attribution such as those related to drought and tropical cyc-lones. It can be expected that, with the continual development of climate models, ongoing improvements to data, and the introduction of new methods in the future, climate change attribution research will develop accordingly. Addi-tionally, further improvement in climate change attribution will facilitate the development of operational attribution systems for extreme events, as well as attribution studies of climate change impacts.展开更多
Changes in terrestrial near-surface wind speed(NSWS)are indicative of the concentrated net effect of climate change and anthropogenic activities.Investigating change mechanisms of NSWS not only furthers the understand...Changes in terrestrial near-surface wind speed(NSWS)are indicative of the concentrated net effect of climate change and anthropogenic activities.Investigating change mechanisms of NSWS not only furthers the understanding of how the atmosphere changes and improves the climate analysis and projection,but also aids the evaluation and application of wind energy resources.Recent advances in studies of the changes and associated mechanisms of the NSWS over China are reviewed in this paper.Some new results have been achieved in understanding the behaviors of the NSWS changes.The NSWS over China has experienced a decrease in the past 40 years and a recovery in the recent decade,exhibiting large regional and seasonal differences.Understanding of the mechanisms of the NSWS changes has been improved in several aspects;for example,it is found that the reduced NSWS over China is due to the weakening of the pressure-gradient force(PGF)attributed to variations in large-scale ocean–atmosphere circulations(LOACs)as well as the increase of surface roughness due to the land use and cover change(LUCC).The main methods used to analyze the NSWS changes and corresponding mechanisms are also elucidated and discussed.However,studies are still lacking on the mechanisms for multi-timescale(seasonal,interannual,decadal,multidecadal)variations in the NSWS over China,and it remains unknown about the contributions of different forcing factors to the NSWS changes.Finally,key scientific issues regarding our understanding of the NSWS changes are proposed for future investigation.展开更多
The Nobel Prize in Physics 2021 was awarded jointly to Syukuro Manabe,Klaus Hasselmann,and Giorgio Parisi for their groundbreaking contributions to our understanding of complex systems.This is the first time that clim...The Nobel Prize in Physics 2021 was awarded jointly to Syukuro Manabe,Klaus Hasselmann,and Giorgio Parisi for their groundbreaking contributions to our understanding of complex systems.This is the first time that climate scientists were awarded the Nobel Physics Prize.Here,we present the evolution of climate science in the past~200 years and highlight the landmarks of the developments in advancing our understanding of climate change,placing the pioneering contributions of Manabe and Hasselmann into a historical perspective.The backbone of modern climate science is further discussed in the context of the development of the discipline from the discovery of the greenhouse effect to the formation of Earth system science.Perspectives on the future development of climate science are also`presented.展开更多
Understanding the impact of anthropogenic climate change on drought is of great significance to the prevention of its adverse effects.Two drought indices,standardized precipitation index(SPI)and standardized precipita...Understanding the impact of anthropogenic climate change on drought is of great significance to the prevention of its adverse effects.Two drought indices,standardized precipitation index(SPI)and standardized precipitation evapotranspiration index(SPEI),are used here for the detection and attribution of autumn droughts in China,and for the exploration of the role played by the anthropogenic climate change.SPI is only related to precipitation,but SPEI involves both precipitation and potential evapotranspiration.For their trend’s spatial patterns,the historical simulations(including all forcings,noted as ALL)from 11 models of the Coupled Model Intercomparison Project phase 6,as an ensemble,are able to reproduce their observational counterpart.SPI shows wetting trend in the north of 35°N and drying trend in the south.SPEI shows drying trend in almost whole China.The drying trend in historical simulations ALL is significantly stronger,compared with the counterpart from the accompanying simulations(called NAT)with only natural forcings implemented.This result clearly indicates that anthropogenic climate change plays a dominant role in the enhancement of autumn drought in China.A more rigorous detection work is also performed with the signal’s fingerprint of ALL(and NAT)projected onto the observation and assessed with the background noise from no external-forcing control simulations.The trend pattern signal in ALL is significantly detected in observation for both SPI and SPEI,with a more pronounced signal in SPEI than in SPI,while the signal of NAT is not detected for neither SPI nor SPEI.Finally,extreme droughts(with indices beyond-2)are assessed in terms of probability ratio between ALL and NAT.It is shown that the anthropogenic precipitation change plays a leading role in the south of 35°N,while the anthropogenic temperature change leads in the north.展开更多
基金supported by the National Basic Research Program of China(2010CB428406)the Ministry of Water Resources Commonwealth Project (200801001)
文摘The progress and advances of the detection and attribution of changes in the hydrological cycle in the IPCC Assessment Reports of WGI and WGII from 1990 to 2007 are reviewed. Accomplishment and endorsed by the joint Expert Meeting on Detection and Attribution in 2009, the Good Practice Guidance Paper （GPGP） for IPCC Lead Authors with its main content and characteristics are briefly introduced. Based on the review and the purpose of the GPGP, some characteristics on the detection and attribution of global warming and of changes in the hydrological cycle are presented.
基金Supported by the National Key Research and Development Program of China(2018YFC1507704,2017YFA0603804)National Natural Science Foundation of China(41905078)。
文摘Northeastern China has experienced a significant increase in summer compound hot and dry events(CHDEs),posing a threat to local agricultural production and sustainable development.This study investigates the detectable anthropogenic signal in the long-term trend of CHDE and quantifies the contribution of different external forcings.A probability-based index(PI)is constructed through the joint probability distribution to measure the severity of CHDE,with lower values representing more severe cases.Response of CHDE to external forcing was assessed with simulations from the Coupled Model Intercomparison Project phase 6(CMIP6).The results show a significant increase in the severity of CHDE over northeastern China during the past decades.The trend of regional averaged PI is-0.28(90%confidence interval:-0.43 to-0.13)per 54 yr and it is well reproduced in the historical forcing simulations.The attribution method of optimal fingerprinting was firstly applied to a two-signal configuration with anthropogenic forcing and natural forcing;the anthropogenic impact was robustly detected and it explains most of the observed trend of PI.Similarly,three-signal analysis further demonstrated that the anthropogenic greenhouse gases dominantly contribute to the observed change,while the anthropogenic aerosol and natural forcing have almost no contribution to the observed changes.For a compound event concurrently exceeding the 95 th percentile of surface air temperature and precipitation reversal in the current period,its likelihood exhibits little change at 1.5℃global warming,but almost doubled at 2.0℃global warming.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFA0608904)the International Partnership Program of the Chinese Academy of Sciences(Grant Nos.060GJHZ2023079GC and 134111KYSB20160031)+1 种基金supported by the Office of Science,U.S.Department of Energy(DOE)Biological and Environmental Research as part of the Regional and Global Model Analysis program area through the Water Cycle and Climate Extremes Modeling(WACCEM)scientific focus areaoperated for DOE by Battelle Memorial Institute under contract DE-AC05-76RL01830。
文摘The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risks,including floods and droughts.Recent research associated with the implementation of the Global Monsoons Model Intercomparison Project under the umbrella of CMIP6 has advanced our understanding of its historical variability and driving mechanisms.Observational data reveal a 20th-century shift:increased rainfall pre-1950s,followed by aridification and partial recovery post-1980s,driven by both internal variability(e.g.,Atlantic Multidecadal Oscillation)and external forcings(greenhouse gases,aerosols),while ENSO drives interannual variability through ocean-atmosphere interactions.Future projections under greenhouse forcing suggest long-term monsoon intensification,though regional disparities and model uncertainties persist.Models indicate robust trends but struggle to quantify extremes,where thermodynamic effects(warming-induced moisture rise)uniformly boost heavy rainfall,while dynamical shifts(circulation changes)create spatial heterogeneity.Volcanic eruptions and proposed solar radiation modification(SRM)further complicate predictions:tropical eruptions suppress monsoons,whereas high-latitude events alter cross-equatorial flows,highlighting unresolved feedbacks.The emergent constraint approach is booming in terms of correcting future projections and reducing uncertainty with respect to the global monsoons.Critical challenges remain.Model biases and sparse 20th-century observational data hinder accurate attribution.The interplay between natural variability and anthropogenic forcings,along with nonlinear extreme precipitation risks under warming,demands deeper mechanistic insights.Additionally,SRM’s regional impacts and hemispheric monsoon interactions require systematic evaluation.Addressing these gaps necessitates enhanced observational networks,refined climate models,and interdisciplinary efforts to disentangle multiscale drivers,ultimately improving resilience strategies for monsoon-dependent regions.
基金supported by the National Natural Science Foundation of China(Grant No.42075037 and 42275033)the UK–China Research and Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)-China programme as part of the Newton Fund.
文摘Extreme weather events and their consequential impacts have been a key feature of the climate in recent years in many parts of the world,with many partly attributed to ongoing global-scale warming.The past year,2022,has been no exception,with further records being broken.The year was marked by unprecedented heatwaves and droughts with highly unusual spatial extent,duration and intensity,with one measure indicating an aggregated and overall intensity of extreme heat events worldwide not seen since at least 1950.The extreme drought measured by surface soil moisture covered 47.3%of global land areas in 2022,which was the second most widespread year since 1980.Here,we examine notable events of the year in five major regions of the world:China’s Yangtze River region,western Europe,the western U.S.,the Horn of Africa and central South America.For each event,we review the potential roles of circulation,oceanic forcing(especially the“triple-dip”La Niña)and anthropogenic climate change,with an aim of understanding the extreme events in 2022 from a global perspective.This will serve as a reference for mechanism understanding,prediction and attribution of extreme events.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(Grant No.2019QZKK0102)the K.C.WONG Education Foundation.This work also contributes to the U.K.-China Research and Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund.
文摘The year 2021 was recorded as the 6th warmest since 1880.In addition to large-scale warming,2021 will be remembered for its unprecedented climate extremes.Here,a review of selected high-impact climate extremes in 2021,with a focus on China,along with an extension to extreme events in North America and Europe is presented.Nine extreme events that occurred in 2021 in China are highlighted,including a rapid transition from cold to warm extremes and sandstorms in spring,consecutive drought in South China and severe thunderstorms in eastern China in the first half of the year,extremely heavy rainfall over Henan Province and Hubei Province during summer,as well as heatwaves,persistent heavy rainfall,and a cold surge during fall.Potential links of extremes in China to four global-scale climate extremes and the underlying physical mechanisms are discussed here,providing insights to understand climate extremes from a global perspective.This serves as a reference for climate event attribution,process understanding,and high-resolution modeling of extreme events.
基金supported by the National Natural Science Foundation of China[grant number 41875105]the National Key R&D Program of China[grant number 2018YFA0606002]the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars[grant number BK20211540]。
文摘The frequent and rapid onset of flash drought poses a serious threat to agriculture and ecosystems.Detecting human influences on flash droughts and estimating their future risks under climate change have attracted great attention.Focusing on a record-breaking flash drought event in the southeastern coastal region of China in summer 2020,the authors found that the suppression of convective precipitation and high temperature caused by the persistent high geopotential height anomalies and land-atmosphere dry coupling were important reasons for the rapid onset and strong intensity of the flash drought.Event attribution analysis with the latest CMIP6 data showed that anthropogenic climate change has not only increased the likelihood of an onset speed and intensity like those of the 2020 flash drought event,by about 93%±20%and 18%±15%,respectively,but also increased the chance of their simultaneous occurrence,by about 86%±38%,according to their joint probability distribution.Under a business-as-usual future scenario(SSP2-4.5),the likelihood of such an onset speed,intensity,and their simultaneous occurrence will further increase,by 85%±33%,49%±8%,and 81%±48%,respectively,as compared with current climate conditions.This study highlights the importance of anthropogenic climate change for accelerating and intensifying flash drought in the southeastern coastal region of China.
基金support from the National Natural Science Foundation of China(Grant No.42175070)。
文摘While being successful in the detection and attribution of climate change,the optimal fingerprinting method(OFM)may have some limitations from a physics-and-dynamics-based viewpoint.Here,an analysis is made on the linearity,noninteraction,and stationary-variability assumptions adopted by OFM.It is suggested that furthering OFM needs a viewpoint beyond statistical science,and the method should be combined with theoretical tools in the dynamics and physics of the Earth system,so as to be applied for the detection and attribution of nonlinear climate change including tipping elements within the Earth system.
基金Supported by the National Key Research and Development Program of China(2017YFA0603501)National Natural Science Foundation of China(41575094)Basic Research to Operation Funds of the Chinese Academy of Meteorological Sciences(2017Y006)
文摘This paper reviews recent progress in climate change attribution studies. The focus is on the attribution of ob-served long-term changes in surface temperature, precipitation, circulation, and extremes, as well as that of specific extreme weather and climate events. Based on new methods and better models and observations, the latest studies ftLrther verify the conclusions on climate change attribution in the IPCC AR5, and enrich the evidence for anthropo-genie influences on weather and climate variables and extremes. The uncertainty of global temperature change attrib- utable to anthropogenic forcings lies in the considerable uncertainty of estimated total radiative forcing due to aero- sols, while the uncertainty of precipitation change attribution arises from the limitations of observation and model simulations along with influences from large internal variability. In terms of extreme weather and climate events, it is clear that attribution studies have provided important new insights into the changes in the intensity or frequency of some of these events caused by anthropogenic climate change. The framing of the research question, the methods se- lected, and the model and statistical methods used all have influences on the results and conclusions drawn in an event attribution study. Overall, attribution studies in China remain inadequate because of limited research focus and the complexity of the monsoon climate in East Asia. Attribution research in China has focused mainly on changes or events related to temperature, such as the attribution of changes in mean and extreme temperature and individual heat wave events. Some progress has also been made regarding the pattern of changes in precipitation and individual ex-treme rainfall events in China. Nonetheless, gaps remain with respect to the attribution of changes in extreme precip-itation, circulation, and drought, as well as to the event attribution such as those related to drought and tropical cyc-lones. It can be expected that, with the continual development of climate models, ongoing improvements to data, and the introduction of new methods in the future, climate change attribution research will develop accordingly. Addi-tionally, further improvement in climate change attribution will facilitate the development of operational attribution systems for extreme events, as well as attribution studies of climate change impacts.
基金Supported by the National Key Research and Development Program of China(2018YFA0606004 and 2016YFA0600403)National Natural Science Foundation of China(42005023,41875178,41775087,and 41675149)China Postdoctoral Science Foundation(2019M660761)。
文摘Changes in terrestrial near-surface wind speed(NSWS)are indicative of the concentrated net effect of climate change and anthropogenic activities.Investigating change mechanisms of NSWS not only furthers the understanding of how the atmosphere changes and improves the climate analysis and projection,but also aids the evaluation and application of wind energy resources.Recent advances in studies of the changes and associated mechanisms of the NSWS over China are reviewed in this paper.Some new results have been achieved in understanding the behaviors of the NSWS changes.The NSWS over China has experienced a decrease in the past 40 years and a recovery in the recent decade,exhibiting large regional and seasonal differences.Understanding of the mechanisms of the NSWS changes has been improved in several aspects;for example,it is found that the reduced NSWS over China is due to the weakening of the pressure-gradient force(PGF)attributed to variations in large-scale ocean–atmosphere circulations(LOACs)as well as the increase of surface roughness due to the land use and cover change(LUCC).The main methods used to analyze the NSWS changes and corresponding mechanisms are also elucidated and discussed.However,studies are still lacking on the mechanisms for multi-timescale(seasonal,interannual,decadal,multidecadal)variations in the NSWS over China,and it remains unknown about the contributions of different forcing factors to the NSWS changes.Finally,key scientific issues regarding our understanding of the NSWS changes are proposed for future investigation.
基金supported by the National Natural Science Foundation of China(Grant No.41988101)K.C.Wong Education Foundation。
文摘The Nobel Prize in Physics 2021 was awarded jointly to Syukuro Manabe,Klaus Hasselmann,and Giorgio Parisi for their groundbreaking contributions to our understanding of complex systems.This is the first time that climate scientists were awarded the Nobel Physics Prize.Here,we present the evolution of climate science in the past~200 years and highlight the landmarks of the developments in advancing our understanding of climate change,placing the pioneering contributions of Manabe and Hasselmann into a historical perspective.The backbone of modern climate science is further discussed in the context of the development of the discipline from the discovery of the greenhouse effect to the formation of Earth system science.Perspectives on the future development of climate science are also`presented.
基金Supported by the National Key Research and Development Program of China(2018YFC1507704)。
文摘Understanding the impact of anthropogenic climate change on drought is of great significance to the prevention of its adverse effects.Two drought indices,standardized precipitation index(SPI)and standardized precipitation evapotranspiration index(SPEI),are used here for the detection and attribution of autumn droughts in China,and for the exploration of the role played by the anthropogenic climate change.SPI is only related to precipitation,but SPEI involves both precipitation and potential evapotranspiration.For their trend’s spatial patterns,the historical simulations(including all forcings,noted as ALL)from 11 models of the Coupled Model Intercomparison Project phase 6,as an ensemble,are able to reproduce their observational counterpart.SPI shows wetting trend in the north of 35°N and drying trend in the south.SPEI shows drying trend in almost whole China.The drying trend in historical simulations ALL is significantly stronger,compared with the counterpart from the accompanying simulations(called NAT)with only natural forcings implemented.This result clearly indicates that anthropogenic climate change plays a dominant role in the enhancement of autumn drought in China.A more rigorous detection work is also performed with the signal’s fingerprint of ALL(and NAT)projected onto the observation and assessed with the background noise from no external-forcing control simulations.The trend pattern signal in ALL is significantly detected in observation for both SPI and SPEI,with a more pronounced signal in SPEI than in SPI,while the signal of NAT is not detected for neither SPI nor SPEI.Finally,extreme droughts(with indices beyond-2)are assessed in terms of probability ratio between ALL and NAT.It is shown that the anthropogenic precipitation change plays a leading role in the south of 35°N,while the anthropogenic temperature change leads in the north.
