Forests play a critical role in mitigating cli-mate change by sequestering carbon,yet their responses to environmental shifts remain complex and multifaceted.This special issue,“Tree Rings,Forest Carbon Sink,and Clim...Forests play a critical role in mitigating cli-mate change by sequestering carbon,yet their responses to environmental shifts remain complex and multifaceted.This special issue,“Tree Rings,Forest Carbon Sink,and Climate Change,”compiles 41 interdisciplinary studies exploring forest-climate interactions through dendrochro-nological and ecological approaches.It addresses climate reconstruction(e.g.,temperature,precipitation,isotopes)using tree-ring proxies,species-specific and age-dependent growth responses to warming and drought,anatomical adap-tations,and methodological innovations in isotope analysis and multi-proxy integration.Key findings reveal ENSO/AMO modulation of historical climates,elevation-and latitude-driven variability in tree resilience,contrasting carbon dynamics under stress,and projected habitat shifts for vulnerable species.The issue underscores forests’dual role as climate archives and carbon regulators,offering insights for adaptive management and nature-based climate solutions.Contributions bridge micro-scale physiological processes to macro-scale ecological modeling,advancing sustainable strategies amid global environmental challenges.展开更多
Spring phenology is one of the most sensitive ecological indicators of forest responses to climate warming.Understanding the precise climatic drivers of bud break in keystone species is crucial for developing robust p...Spring phenology is one of the most sensitive ecological indicators of forest responses to climate warming.Understanding the precise climatic drivers of bud break in keystone species is crucial for developing robust phenological models and predicting future ecological and economic impacts.In this study,spring bud phenology was recorded 2020-2022 of 42 provenances of sugar maple(Acer saccharum Marsh.)originating from the northern range of the species in Quebec,Canada.The effect of temperature on budburst timing was assessed,and based on the observed linear relationship,we reconstructed the budburst timings of maple forests located between 45°and 49°N latitude and-70°and-76°W longitude over the past two decades.In the common garden the entire bud break process lasted between 20 and 40 d.Bud swelling occurred mid-April to mid-May,on average 5 d earlier in the southern and warmer stands.A strong correlation was observed between bud swelling dates and mean temperatures in the last two weeks of April,with temperature explaining 90%of the variance.An increase of 1℃in mean temperature during this period advanced budburst by 4 d.At the northern limit of sugar maple,late April had an average temperature between 1.6 and 8.7℃during 2003-2022,resulting in an estimated variability of 28 d in bud swelling from early April to early May.Our findings confirm that late April temperatures play a major role in the reactivation of sugar maple at its northern range.The earlier onset of leaf development under warming conditions could increase the risk of late frost damage,with consequences for maple syrup production and species distribution.展开更多
Long-term temperature variations inferred from high-resolution proxies provide an important context to evaluate the intensity of current warming.However,tem-perature reconstructions in humid southeastern China are sca...Long-term temperature variations inferred from high-resolution proxies provide an important context to evaluate the intensity of current warming.However,tem-perature reconstructions in humid southeastern China are scarce and particularly lack long-term data,limiting us to obtain a complete picture of regional temperature evolution.In this study,we present a well-verified reconstruction of winter-spring(January–April)minimum temperatures over southeastern China based on stable carbon isotopic(δ^(13)C)records of tree rings from Taxus wallichiana var.mairei from 1860 to 2014.This reconstruction accounted for 56.4%of the total observed variance.Cold periods occurred during the 1860s–1910s and 1960s–1970s.Although temperatures have had an upward trend since the 1920s,most of the cold extremes were in recent decades.The El Niño-Southern Oscillation(ENSO)variance acted as a key modulator of regional winter-spring minimum temperature variability.However,teleconnections between them were a nonlinear process,i.e.,a reduced or enhanced ENSO variance may result in a weakened or intensified temperature-ENSO relationship.展开更多
Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surface temperature （SST） pattern, such as the Pacific Decadal Oscillation （PDO）. The PDO may be ...Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surface temperature （SST） pattern, such as the Pacific Decadal Oscillation （PDO）. The PDO may be associated with the North Pacific branch of the Thermohaline Circulation （THC）. Great earthquakes （M 〉8）, particularly along the route of the THC, might modulate the vertical mixing and bring deep, cold water to surface, contributing to multi-decadal changes in surface currents and the PDO. This may eventually lead to multi-decadal climate changes. We tested this hypothesis for the Pacific Ocean where great earthquakes have been frequently recorded. We found associations between the PDO and recurrent earthquakes along the route of the deep currents of the THC in the modern period since 1900, and relationships between hydroclimate change in Monsoonal Asia and historical earthquakes since 1300. However, it should be noted that this hypothesis is very preliminary and has many gaps that needs further evidences from more observational records and modeling studies.展开更多
Multi-year El Nino events are the key drivers of persistent extreme weather and climate anomalies worldwide.Understanding the factors influencing multi-year El Nino variations over the past millennium is crucial for p...Multi-year El Nino events are the key drivers of persistent extreme weather and climate anomalies worldwide.Understanding the factors influencing multi-year El Nino variations over the past millennium is crucial for predicting its future occurrences in warmer climates.This study reconstructs the frequency of multi-year El Nino events from 848 to 1992 CE using a global tree-ring network.The ratio of multi-year El Nino events to all El Nino events in recent decades(~30%)is not the highest over the past millennium,and the peak occurrences are observed during 1500-1550 and 1620-1670(~60%).State-of-the-art model simulations suggest that multidecadal variations in the frequency of multi-year El Nino events over the past millennium are primarily driven by internal variability associated with the Interdecadal Pacific Oscillation(IPO),whereas external forcing plays a minimal role.During positive IPO phases,an enhanced inter-basin sea surface temperature(SST)gradient between the tropical Pacific and other oceans increases the occurrence of westerly wind anomalies in the equatorial western Pacific during the post-El Nino spring,fostering persistent SST warming and the development of multi-year El Nino events.Our results suggest that the incorporation of IPO phase shifts may improve projections of multidecadal variations in multi-year El Nino events.展开更多
The stable carbon isotope composition of cellulose(δ^(13)Ccell)in fossil wood is valuable for reconstructing past climatic and ecological changes,on seasonal to decadal timescales.However,extracting cellulose from fo...The stable carbon isotope composition of cellulose(δ^(13)Ccell)in fossil wood is valuable for reconstructing past climatic and ecological changes,on seasonal to decadal timescales.However,extracting cellulose from fossil wood is challenging,leading to a lack ofδ^(13)Ccell data over deep time;moreover,there is a debate about whether the stable carbon isotope composition of whole wood(δ^(13)Cwood)can reliably reflect past paleoclimatic or palaeoecological conditions.Here,we present an improved method for extracting cellulose from fossil wood.We initially used conventional methods to extract cellulose from a fossil wood sample a drill core from the Yuncheng Basin,near the Chinese Loess Plateau;however,we were unsuccessful.Subsequently,we successfully extracted cellulose and recovered 94%of the cellulose after modifying the conventional procedure.This involved increasing the reaction time during lignin removal,reducing the concentration of NaOH solution during hemicellulose removal,and employing multiple centrifugation steps for sample separation instead of a single step.We examined the relationship betweenδ^(13)Ccell andδ^(13)Cwood values(n=136),and the results revealed a positive correlation between them(R^(2)=0.51,P<0.001).This indicates thatδ^(13)Cwood is a dependable proxy for qualitative paleoclimatic reconstruction.However,the apparent enrichment factorεbetweenδ^(13)Ccell andδ^(13)Cwood values varied between samples,highlighting the need for caution when using records ofδ^(13)Cwood for quantitative paleoenvironmental reconstruction.展开更多
The Tibetan Plateau(TP),known as the“Third Pole”of the Earth and“Asian Water Tower”,is the magnifier of global climate change and birthplace of many large rivers in Asia.There are unique alpine wetlands on the TP,...The Tibetan Plateau(TP),known as the“Third Pole”of the Earth and“Asian Water Tower”,is the magnifier of global climate change and birthplace of many large rivers in Asia.There are unique alpine wetlands on the TP,accounting for 20%of Chinese wetlands area,and the lakes alone constitute half of the national lake area.Wetlands are critical to human survival and development as one of the three major ecosystems[1].展开更多
Three ring-width chronologies were developed from Qilian Juniper （Sabina przewalskii Kom.） at the upper treeline along a west-east gradient in the Anyemaqen Mountains. Most chronological statistics, except for mean ...Three ring-width chronologies were developed from Qilian Juniper （Sabina przewalskii Kom.） at the upper treeline along a west-east gradient in the Anyemaqen Mountains. Most chronological statistics, except for mean sensitivity （MS）, decreased from west to east. The first principal component （PC1） Ioadings indicated that stands in a similar climate condition were most important to the variability of radial growth. PC2 Ioadings decreased from west to east, suggesting the difference of tree-growth between eastern and western Anyemaqen Mountains. Correlations between standard chronologies and climatic factors revealed different climatic influences on radial growth along a west-east gradient in the study area. Temperature of warm season （July-August） was important to the radial growth at the upper treeline in the whole study area. Precipitation of current May was an important limiting factor of tree growth only in the western （drier） upper treeline, whereas precipitation of current September limited tree growth in the eastern （wetter） upper treeline. Response function analysis results showed that there were regional differences between tree growth and climatic factors in various sampling sites of the whole study area. Temperature and precipitation were the important factors influencing tree growth in western （drier） upper treeline. However, tree growth was greatly limited by temperature at the upper treeline in the middle area, and was more limited by precipitation than temperature in the eastern （wetter） upper treeline.展开更多
Fossil pollen records from 45 sites across China were evaluated and synthesized to document vegetation and climate change during Marine Isotope Stage 3(MIS 3)at 60–27 ka and to understand the large-scale controls.Dur...Fossil pollen records from 45 sites across China were evaluated and synthesized to document vegetation and climate change during Marine Isotope Stage 3(MIS 3)at 60–27 ka and to understand the large-scale controls.During MIS3, vegetation type was dominantly forest in eastern China, forest steppe/meadow in the north and Tibetan Plateau, and steppe desert in northwestern arid China. We developed a semi-quantitative vegetation index to reflect change in plant abundance(by inferring the general climate conditions), with a vegetation score from 1to 3 based on the different vegetation types inferred from pollen data at individual sites at intervals of 2,000 years.The reconstructed vegetation index shows higher values during MIS 3, especially during the period 53–40 ka, than at the Last Glacial Maximum. Our results also suggest that climate on the basis of vegetation change was cooler and drier during MIS 3 than during the Holocene optimum;however, MIS 3 vegetation was probably similar to modern vegetation. The close relationship between vegetation change, insolation and Asian summer monsoon strength suggests that climate variations, probably in both temperature and precipitation, are the primary drivers of regional vegetation change. Additional well-dated, high-resolution palaeoclimate records from many locations across China will be needed to understand the vegetation change and climate forcings on millennial and centennial scales within MIS 3.展开更多
The Earth’s three poles,the North Pole,South Pole,and Third Pole(i.e.,the Tibetan Plateau and its surroundings),hold the largest amount of fresh water on Earth as glaciers,sea ice,and snow.They are sensitive to clima...The Earth’s three poles,the North Pole,South Pole,and Third Pole(i.e.,the Tibetan Plateau and its surroundings),hold the largest amount of fresh water on Earth as glaciers,sea ice,and snow.They are sensitive to climate change.However,the linkages between climate variations of the three poles,particularly between the South Pole and Third Pole,remain largely unknown.The temperatures at 200 hPa over the three poles are the highest in the summer and are less affected by surface conditions,which could reflect large-scale dynamic linkages.Temperatures at 200 hPa peak the three poles during their respective hemispheric summer and exhibit in-phase variations on interdecadal timescales(10–100 years).The 200 hPa temperatures over the North Pole and South Pole were significantly correlated with the Brewer-Dobson circulation(BDC),which transports stratospheric ozone poleward,heating the air at 200 hPa.Tropopause warming over the Third Pole was found to enhance the poleward BDC,particularly to the South Pole,linking the Third Pole’s climate to the other two poles.Additionally,the Interdecadal Pacific Oscillation(IPO)also exhibits links with the 200 hPa temperatures of the three poles.展开更多
1 Introduction The output of scientific research in China ranks second in the world according to the Nature Index of 2015(www.nature.com/nature/journal/v522/n7556_supp/full/522S34a.html)and the ISI Web of Science(http...1 Introduction The output of scientific research in China ranks second in the world according to the Nature Index of 2015(www.nature.com/nature/journal/v522/n7556_supp/full/522S34a.html)and the ISI Web of Science(http://thomsonreuters.com).Although important advances have been made,it should be noted that China has the展开更多
基金supported by the Outstanding Action Plan of Chinese Sci-tech Journals(Grant No.OAP-C-077).
文摘Forests play a critical role in mitigating cli-mate change by sequestering carbon,yet their responses to environmental shifts remain complex and multifaceted.This special issue,“Tree Rings,Forest Carbon Sink,and Climate Change,”compiles 41 interdisciplinary studies exploring forest-climate interactions through dendrochro-nological and ecological approaches.It addresses climate reconstruction(e.g.,temperature,precipitation,isotopes)using tree-ring proxies,species-specific and age-dependent growth responses to warming and drought,anatomical adap-tations,and methodological innovations in isotope analysis and multi-proxy integration.Key findings reveal ENSO/AMO modulation of historical climates,elevation-and latitude-driven variability in tree resilience,contrasting carbon dynamics under stress,and projected habitat shifts for vulnerable species.The issue underscores forests’dual role as climate archives and carbon regulators,offering insights for adaptive management and nature-based climate solutions.Contributions bridge micro-scale physiological processes to macro-scale ecological modeling,advancing sustainable strategies amid global environmental challenges.
基金supported by the Natural Sciences and Engineering Research Council of Canada(research programs Alliance and Discovery grants),the Fonds de Recherche du Québec-Sociétéet culture,the Ministère des Ressources naturelles et des Forêts du Québec,Syndicat des producteurs des bois du Saguenay-Lac-Saint-Jean,the Producteurs et productrices acéricoles du Québec,the Centre ACER,the Fondation de l’Universitédu QuébecàChicoutimisupported by the National Science Foundation of China(42301058)。
文摘Spring phenology is one of the most sensitive ecological indicators of forest responses to climate warming.Understanding the precise climatic drivers of bud break in keystone species is crucial for developing robust phenological models and predicting future ecological and economic impacts.In this study,spring bud phenology was recorded 2020-2022 of 42 provenances of sugar maple(Acer saccharum Marsh.)originating from the northern range of the species in Quebec,Canada.The effect of temperature on budburst timing was assessed,and based on the observed linear relationship,we reconstructed the budburst timings of maple forests located between 45°and 49°N latitude and-70°and-76°W longitude over the past two decades.In the common garden the entire bud break process lasted between 20 and 40 d.Bud swelling occurred mid-April to mid-May,on average 5 d earlier in the southern and warmer stands.A strong correlation was observed between bud swelling dates and mean temperatures in the last two weeks of April,with temperature explaining 90%of the variance.An increase of 1℃in mean temperature during this period advanced budburst by 4 d.At the northern limit of sugar maple,late April had an average temperature between 1.6 and 8.7℃during 2003-2022,resulting in an estimated variability of 28 d in bud swelling from early April to early May.Our findings confirm that late April temperatures play a major role in the reactivation of sugar maple at its northern range.The earlier onset of leaf development under warming conditions could increase the risk of late frost damage,with consequences for maple syrup production and species distribution.
基金supported by the National Science Foundation of China(42101082)the Science Foundation of Fujian Province(2023J01496).
文摘Long-term temperature variations inferred from high-resolution proxies provide an important context to evaluate the intensity of current warming.However,tem-perature reconstructions in humid southeastern China are scarce and particularly lack long-term data,limiting us to obtain a complete picture of regional temperature evolution.In this study,we present a well-verified reconstruction of winter-spring(January–April)minimum temperatures over southeastern China based on stable carbon isotopic(δ^(13)C)records of tree rings from Taxus wallichiana var.mairei from 1860 to 2014.This reconstruction accounted for 56.4%of the total observed variance.Cold periods occurred during the 1860s–1910s and 1960s–1970s.Although temperatures have had an upward trend since the 1920s,most of the cold extremes were in recent decades.The El Niño-Southern Oscillation(ENSO)variance acted as a key modulator of regional winter-spring minimum temperature variability.However,teleconnections between them were a nonlinear process,i.e.,a reduced or enhanced ENSO variance may result in a weakened or intensified temperature-ENSO relationship.
基金funded by the Nordic Top-level Research Initiative CRAICC(Cryosphere-Atmosphere Interactions in A Changing Arctic Climate)the National Natural Science Foundation of China(Nos.41001115 and 41210002)
文摘Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surface temperature （SST） pattern, such as the Pacific Decadal Oscillation （PDO）. The PDO may be associated with the North Pacific branch of the Thermohaline Circulation （THC）. Great earthquakes （M 〉8）, particularly along the route of the THC, might modulate the vertical mixing and bring deep, cold water to surface, contributing to multi-decadal changes in surface currents and the PDO. This may eventually lead to multi-decadal climate changes. We tested this hypothesis for the Pacific Ocean where great earthquakes have been frequently recorded. We found associations between the PDO and recurrent earthquakes along the route of the deep currents of the THC in the modern period since 1900, and relationships between hydroclimate change in Monsoonal Asia and historical earthquakes since 1300. However, it should be noted that this hypothesis is very preliminary and has many gaps that needs further evidences from more observational records and modeling studies.
基金supported by the National Natural Science Foundation of China(Grant Nos.42425101 and 42301058)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(Grant No.GZC20250218)+2 种基金the Fujian Institute for Cross-Straits Integrated Development(Grant No.LARH24JBO7)the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.SML2023SP209)the Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies(Grant No.2023B1212060019)。
文摘Multi-year El Nino events are the key drivers of persistent extreme weather and climate anomalies worldwide.Understanding the factors influencing multi-year El Nino variations over the past millennium is crucial for predicting its future occurrences in warmer climates.This study reconstructs the frequency of multi-year El Nino events from 848 to 1992 CE using a global tree-ring network.The ratio of multi-year El Nino events to all El Nino events in recent decades(~30%)is not the highest over the past millennium,and the peak occurrences are observed during 1500-1550 and 1620-1670(~60%).State-of-the-art model simulations suggest that multidecadal variations in the frequency of multi-year El Nino events over the past millennium are primarily driven by internal variability associated with the Interdecadal Pacific Oscillation(IPO),whereas external forcing plays a minimal role.During positive IPO phases,an enhanced inter-basin sea surface temperature(SST)gradient between the tropical Pacific and other oceans increases the occurrence of westerly wind anomalies in the equatorial western Pacific during the post-El Nino spring,fostering persistent SST warming and the development of multi-year El Nino events.Our results suggest that the incorporation of IPO phase shifts may improve projections of multidecadal variations in multi-year El Nino events.
基金support for this research was provided by the National Natural Science Foundation of China(Grant No.42072211)the Fundamental Research Funds for the Central Universities,China(No.lzujbky-2021-ey12).
文摘The stable carbon isotope composition of cellulose(δ^(13)Ccell)in fossil wood is valuable for reconstructing past climatic and ecological changes,on seasonal to decadal timescales.However,extracting cellulose from fossil wood is challenging,leading to a lack ofδ^(13)Ccell data over deep time;moreover,there is a debate about whether the stable carbon isotope composition of whole wood(δ^(13)Cwood)can reliably reflect past paleoclimatic or palaeoecological conditions.Here,we present an improved method for extracting cellulose from fossil wood.We initially used conventional methods to extract cellulose from a fossil wood sample a drill core from the Yuncheng Basin,near the Chinese Loess Plateau;however,we were unsuccessful.Subsequently,we successfully extracted cellulose and recovered 94%of the cellulose after modifying the conventional procedure.This involved increasing the reaction time during lignin removal,reducing the concentration of NaOH solution during hemicellulose removal,and employing multiple centrifugation steps for sample separation instead of a single step.We examined the relationship betweenδ^(13)Ccell andδ^(13)Cwood values(n=136),and the results revealed a positive correlation between them(R^(2)=0.51,P<0.001).This indicates thatδ^(13)Cwood is a dependable proxy for qualitative paleoclimatic reconstruction.However,the apparent enrichment factorεbetweenδ^(13)Ccell andδ^(13)Cwood values varied between samples,highlighting the need for caution when using records ofδ^(13)Cwood for quantitative paleoenvironmental reconstruction.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0608 and 2019QZKK0604)。
文摘The Tibetan Plateau(TP),known as the“Third Pole”of the Earth and“Asian Water Tower”,is the magnifier of global climate change and birthplace of many large rivers in Asia.There are unique alpine wetlands on the TP,accounting for 20%of Chinese wetlands area,and the lakes alone constitute half of the national lake area.Wetlands are critical to human survival and development as one of the three major ecosystems[1].
基金the National Natural Science Foundation of China (NSFC)(40671191 and 90502008)the Chinese NSFC Innovation Team Project(40721061)+1 种基金Program for New Century Excellent Talents in University (NCET-05-0888)the Chinese 111 Project (B06026)
文摘Three ring-width chronologies were developed from Qilian Juniper （Sabina przewalskii Kom.） at the upper treeline along a west-east gradient in the Anyemaqen Mountains. Most chronological statistics, except for mean sensitivity （MS）, decreased from west to east. The first principal component （PC1） Ioadings indicated that stands in a similar climate condition were most important to the variability of radial growth. PC2 Ioadings decreased from west to east, suggesting the difference of tree-growth between eastern and western Anyemaqen Mountains. Correlations between standard chronologies and climatic factors revealed different climatic influences on radial growth along a west-east gradient in the study area. Temperature of warm season （July-August） was important to the radial growth at the upper treeline in the whole study area. Precipitation of current May was an important limiting factor of tree growth only in the western （drier） upper treeline, whereas precipitation of current September limited tree growth in the eastern （wetter） upper treeline. Response function analysis results showed that there were regional differences between tree growth and climatic factors in various sampling sites of the whole study area. Temperature and precipitation were the important factors influencing tree growth in western （drier） upper treeline. However, tree growth was greatly limited by temperature at the upper treeline in the middle area, and was more limited by precipitation than temperature in the eastern （wetter） upper treeline.
基金supported by the Hundred Talents Programme of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(41125006,41330105)Humboldt Research Fellowship for Experienced Researchers
文摘Fossil pollen records from 45 sites across China were evaluated and synthesized to document vegetation and climate change during Marine Isotope Stage 3(MIS 3)at 60–27 ka and to understand the large-scale controls.During MIS3, vegetation type was dominantly forest in eastern China, forest steppe/meadow in the north and Tibetan Plateau, and steppe desert in northwestern arid China. We developed a semi-quantitative vegetation index to reflect change in plant abundance(by inferring the general climate conditions), with a vegetation score from 1to 3 based on the different vegetation types inferred from pollen data at individual sites at intervals of 2,000 years.The reconstructed vegetation index shows higher values during MIS 3, especially during the period 53–40 ka, than at the Last Glacial Maximum. Our results also suggest that climate on the basis of vegetation change was cooler and drier during MIS 3 than during the Holocene optimum;however, MIS 3 vegetation was probably similar to modern vegetation. The close relationship between vegetation change, insolation and Asian summer monsoon strength suggests that climate variations, probably in both temperature and precipitation, are the primary drivers of regional vegetation change. Additional well-dated, high-resolution palaeoclimate records from many locations across China will be needed to understand the vegetation change and climate forcings on millennial and centennial scales within MIS 3.
基金supported by the National Natural Science Foundation of China(Grant Nos.41822101,41888101,41971022&41772180)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB26020000 and XDA20060401)+2 种基金the State Administration of Foreign Experts Affairs of China(Grant No.GS20190157002)fellowship for the National Youth Talent Support Program of China(Ten Thousand People Plan)Youth Talent Program of Fujian Province,and the Innovation Team Project(Grant No.IRTL1705)。
文摘The Earth’s three poles,the North Pole,South Pole,and Third Pole(i.e.,the Tibetan Plateau and its surroundings),hold the largest amount of fresh water on Earth as glaciers,sea ice,and snow.They are sensitive to climate change.However,the linkages between climate variations of the three poles,particularly between the South Pole and Third Pole,remain largely unknown.The temperatures at 200 hPa over the three poles are the highest in the summer and are less affected by surface conditions,which could reflect large-scale dynamic linkages.Temperatures at 200 hPa peak the three poles during their respective hemispheric summer and exhibit in-phase variations on interdecadal timescales(10–100 years).The 200 hPa temperatures over the North Pole and South Pole were significantly correlated with the Brewer-Dobson circulation(BDC),which transports stratospheric ozone poleward,heating the air at 200 hPa.Tropopause warming over the Third Pole was found to enhance the poleward BDC,particularly to the South Pole,linking the Third Pole’s climate to the other two poles.Additionally,the Interdecadal Pacific Oscillation(IPO)also exhibits links with the 200 hPa temperatures of the three poles.
文摘1 Introduction The output of scientific research in China ranks second in the world according to the Nature Index of 2015(www.nature.com/nature/journal/v522/n7556_supp/full/522S34a.html)and the ISI Web of Science(http://thomsonreuters.com).Although important advances have been made,it should be noted that China has the
