Particle number and mass concentrations were measured in Beijing during the winter and summer periods in 2003, together with some other parameters including black carbon (BC) and meteorological conditions. Particle ma...Particle number and mass concentrations were measured in Beijing during the winter and summer periods in 2003, together with some other parameters including black carbon (BC) and meteorological conditions. Particle mass concentrations exhibited low seasonality, and the ratio of PM2.5/PM10 in winter was higher than that in summer. Particle number size distribution (PSD) was characterized by four modes and exhibited low seasonality. BC was well correlated with the number and mass concentrations of accumulation and coarse particles, indicating these size particles are related to anthropogenic activities. Particle mass and number concentrations (except ultra-fine and nucleation particles) followed well the trends of BC concentration for the majority of the day, indicating that most particles were associated with primary emissions. The diurnal number distributions of accumulation and coarse mode particles were characterized by two peaks.展开更多
A δ^（44） Ca curve from shells of the planktonic foraminifera Globigerinoides sacculifer in calcareous biogenic oozes has been extracted from the Nintyeast Ridge in the Indian Ocean since 300 ka. By combining terrig...A δ^（44） Ca curve from shells of the planktonic foraminifera Globigerinoides sacculifer in calcareous biogenic oozes has been extracted from the Nintyeast Ridge in the Indian Ocean since 300 ka. By combining terrigenous inputs（e.g., grain size, magnetic susceptibility, and turbidite frequency） with the oceanic productivity（e.g., biogenic content and Neogloboquadrina dutertrei content）, it is found that the curve＇s variations are closely related to the historical evolution of the oceanic calcium cycle. The δ^（44）Ca value is in lower tendency and has small oscillation during Marine Isotope Stage（MIS） 6, when the supply of terrigenous detrital is highest. In contrast, during MIS 3,5 and 7, the δ^（44） Ca values are in higher tendency, and their fluctuations are consistent with the variations of the productivity proxies. These results suggest that the calcium isotopes are mainly influenced by the input of the Himalayan erosion products to the northern Indian Ocean. In addition, the developmental stages of calcareous planktons may have a secondary impact on the fluctuations of the calcium isotope ratio of sea water.展开更多
Fire is a major type of disturbance that has important influences on ecosystem dynamics and carbon cycles.Yet our understanding of ecosystem fires and their carbon cycle consequences is still limited,largely due to th...Fire is a major type of disturbance that has important influences on ecosystem dynamics and carbon cycles.Yet our understanding of ecosystem fires and their carbon cycle consequences is still limited,largely due to the difficulty of large-scale fire monitoring and the complex interactions between fire,vegetation,climate,and anthropogenic factors.Here,using data from satellite-derived fire observations and ecosystem model simulations,we performed a comprehensive investigation of the spatial and temporal dynamics of China’s ecosystem fire disturbances and their carbon emissions over the past two decades(1997–2016).Satellite-derived results showed that on average about 3.47-4.53×10^(4) km^(2) of the land was burned annually during the past two decades,among which annual burned forest area was about 0.81-1.25×10^(4) km^(2),accounting for 0.33-0.51%of the forest area in China.Biomass burning emitted about 23.02 TgC per year.Compared to satellite products,simulations from the Energy Exascale Earth System Land Model(ELM)strongly overestimated China’s burned area and fire-induced carbon emissions.Annual burned area and fire-induced carbon emissions were high for boreal forest in Northeast China’s Daxing’anling region and subtropical dry forest in South Yunnan,as revealed by both the satellite product and the model simulations.Our results suggest that climate and anthropogenic factors play critical roles in controlling the spatial and seasonal distribution of China’s ecosystem fire disturbances.Our findings highlight the importance of multiple complementary approaches in assessing ecosystem fire disturbance and its carbon consequences.Further studies are required to improve the methods of observing and modelling China’s ecosystem fire disturbances,which will provide valuable information for fire management and ecosystem sustainability in an era when both human activities and the natural environment are rapidly changing.展开更多
四极杆电感耦合等离子体质谱仪(Inductively Coupled Plasma-Quadrupole Mass Spectrometry,简称ICP-QMS)可用于U和Th同位素分析。目前,ICP-QMS能实现精度大约为0.3%(U)和1%(Th)的测量分析,可提供误差在1%～10%的^(230)Th/U年代数据。...四极杆电感耦合等离子体质谱仪(Inductively Coupled Plasma-Quadrupole Mass Spectrometry,简称ICP-QMS)可用于U和Th同位素分析。目前,ICP-QMS能实现精度大约为0.3%(U)和1%(Th)的测量分析,可提供误差在1%～10%的^(230)Th/U年代数据。本文用ICP-QMS分析了采自意大利南都Loreto旧石器地点的4颗马牙化石样品,并对已发表的UTEVA树脂提纯U和Th的流程做了进一步改进,使其适用于动物牙化石样品。样品中的U和Th含量的平均测量精度(2σ)分别为0.3%和0.6%;^(234)U/^(238)U和^(230)Th/^(238)U活度比平均精度(2σ)分别为0.3%和0.8%。数据表明同一颗牙化石的不同组织的U含量可有数量级差别,同时它们的U-Th同位素活度比也可显著地离散(>2σ),从而导致不一致的^(230)Th/U年代结果。如今测定的各牙组织的U-Th同位素数据可用于模拟U的迁移历史;U-系分析与电子自旋共振测年技术相结合或可更好地估计样品的地质年代。展开更多
Work is currently underway to produce a map in Arc GISTM 10 of the mafic dyke swarms and related units(volcanics,sills and layered intrusions)of Russia and adjacent regions at a scale of 1:5,000,000.Over the past
Limiting human-caused global warming to a specific level requires achieving net-zero anthropogenic carbon dioxide(CO_(2))emissions,along with strong reductions in other greenhouse gas(GHG)emissions.This means that any...Limiting human-caused global warming to a specific level requires achieving net-zero anthropogenic carbon dioxide(CO_(2))emissions,along with strong reductions in other greenhouse gas(GHG)emissions.This means that any remaining anthropogenic CO_(2)emissions must be balanced by an equivalent amount of anthropogenic removals.展开更多
Serving as the breadbasket of the Tibetan Plateau,the Middle Reach of the Yarlung Zangbo River basin is confronted withpersistentthreats of desertification,primarily driven by climate change and human activities.To ad...Serving as the breadbasket of the Tibetan Plateau,the Middle Reach of the Yarlung Zangbo River basin is confronted withpersistentthreats of desertification,primarily driven by climate change and human activities.To address this challenge,the Chinese government has implemented afforestation initiatives in this region for over four decades,yielding substantial ecological benefits that support sustainable development.Based on extensive satellite-based observations,we reveal evidence for these positive outcomes from 1982 to 2020 and quantify their contributions.The most immediate effect is attributed to the control of desertification via restoring 59%of the sandy lands along the riverbanks and increasing forest cover from 133.85 to 419.54 km^(2).Additionally,these efforts have progressively enhanced climatic conditions by improving local heat and water conditions since 2000,despite the backdrop of global warming.This is evidenced by a decrease in land surface temperature by 2.64℃ and air temperature 0.3℃,alongside an average increase in volumetric soil moisture by 2.74%and relative humidity by 2.18%.These positive contributions significantly bolstered the region's agricultural productivity,with grain production experiencing rapid growth between 1992 and 2018.Our findings suggest that long-term afforestation efforts effectively regulate local heat and water conditions,thereby supporting sustainable socioeconomic development.展开更多
尽管普遍认为高山生态系统对气候变化的响应非常敏感,但很少有研究探究气候变化对高山植被生产力和土壤侵蚀的影响.基于古生态学记录,探究了全新世中期以来处于东亚季风影响区的太白山高海拔区植被生产力和土壤侵蚀的演变.高分辨率高山...尽管普遍认为高山生态系统对气候变化的响应非常敏感,但很少有研究探究气候变化对高山植被生产力和土壤侵蚀的影响.基于古生态学记录,探究了全新世中期以来处于东亚季风影响区的太白山高海拔区植被生产力和土壤侵蚀的演变.高分辨率高山湖沼记录显示,植被生产力与年平均温度密切相关,而土壤侵蚀主要受到东亚夏季风所带来的降水的影响.即在5800~4000cal. a BP期间,年平均温度较低而夏季降水充沛,高山生态系统表现为低的植被生产力且土壤侵蚀严重.但是,从4000cal. a BP开始,年平均温度升高而夏季降水减少,植被生产力显著提高且土壤侵蚀减缓.这些结果表明,古生态学记录可为研究较长时间尺度上的生态系统服务提供有力证据,可帮助制定气候变化下的生态系统可持续发展政策.展开更多
The Tibetan Plateau(TP)and Arctic permafrost constitute two large reservoirs of organic carbon,but processes which control carbon accumulation within the surface soil layer of these areas would differ due to the inter...The Tibetan Plateau(TP)and Arctic permafrost constitute two large reservoirs of organic carbon,but processes which control carbon accumulation within the surface soil layer of these areas would differ due to the interplay of climate,soil and vegetation type.Here,we synthesized currently available soil carbon data to show that mean organic carbon density in the topsoil(0-10 cm)in TP grassland(3.12±0.52 kg C m^(-2))is less than half of that in Arctic tundra(6.70±1.94 kg C m^(-2)).Such difference is primarily attributed to their difference in radiocarbon-inferred soil carbon turnover times(547 years for TP grassland versus 1609 years for Arctic tundra)rather than to their marginal difference in topsoil carbon inputs.Our findings highlight the importance of improving regional-specific soil carbon turnover and its controlling mechanisms across permafrost affected zones in ecosystem models to fully represent carbon-climate feedback.展开更多
Forests played an important role in carbon sequestration during the past two decades. Using a model tree ensemble method(MTE) to regress the seven reflectance bands of EOS-Terra-MODIS satellite data against country le...Forests played an important role in carbon sequestration during the past two decades. Using a model tree ensemble method(MTE) to regress the seven reflectance bands of EOS-Terra-MODIS satellite data against country level forest biomass carbon density(BCD) of 2001–2005 provided by United Nations' s Forest Resource Assessment(FRA), we developed a global map of forest BCD at 1 km×1 km resolution for both 2001–2005 and 2006–2010. For 2006–2010, the total global forest biomass carbon stock is estimated as 279.6±7.1 Pg C, and the tropical forest biomass carbon stock is estimated as 174.4±5.4 Pg C. During the first decade of the 21 st century, we estimated an increase of global forest biomass of 0.28±0.75 Pg C yr^(-1). Tropical forest biomass carbon stock slightly decreased(-0.31±0.60 Pg C yr^(-1)); by contrast, temperate and boreal forest biomass increased(0.58±0.28 Pg C yr^(-1)) during the same period. Our estimation of the global forest biomass carbon stock and its changes is subject to uncertainties due to lack of extensive ground measurements in the tropics, spatial heterogeneity in large countries, and different definitions of forest. The continuously monitoring of forest biomass carbon stock with MODIS satellite data will provide useful information for detecting forest changes.展开更多
Aims the impacts of future global warming of 1.5℃ and 2℃ on the productivity and carbon(c)storage of grasslands in china are not clear yet,although grasslands in china support~45 million agricultural populations and...Aims the impacts of future global warming of 1.5℃ and 2℃ on the productivity and carbon(c)storage of grasslands in china are not clear yet,although grasslands in china support~45 million agricultural populations and more than 238 million livestock populations,and are sensitive to global warming.Methods this study used a process-based terrestrial ecosystem model named ORcHIDEE to simulate c cycle of alpine meadows and temperate grasslands in china.this model was driven by high-resolution(0.5°×0.5°)climate of global specific warming levels(SWL)of 1.5℃ and 2℃(warmer than pre-industrial level),which is downscaled by Ec-EARtH3-HR v3.1 with sea surface temperature and sea-ice concentration as boundary conditions from IPSL-cM5-LR(low spatial resolution,2.5°×1.5°)Earth system model(ESM).Important Findingscompared with baseline(1971-2005),the mean annual air temperature over chinese grasslands increased by 2.5℃ and 3.7℃ under SWL1.5 and SWL2,respectively.the increase in temperature in the alpine meadow was higher than that in the temperate grassland under both SWL1.5 and SWL2.Precipitation was also shown an increasing trend under SWL2 over most of the chinese grasslands.Strong increases in gross primary productivity(GPP)were simulated in the chinese grasslands,and the mean annual GPP(GPP_(MA))increased by 19.32%and 43.62%under SWL1.5 and SWL2,respectively.the c storage increased by 0.64 Pg c and 1.37 Pg c under SWL1.5 and SWL2 for 50 years simulations.the GPP_(MA) was 0.67_(0.39)^(0.88)(0.82)(model mean_(min) ^(max) (this study)),0.85_(0.45)^(1.24)(0.97)and 0.94_(0.61)^(1.30)(1.17)Pg C year^(−1) under baseline,SWL1.5 and SWL2 modeled by four cMIP5 ESMs(phase 5 of the coupled Model Inter-comparison Project Earth System Models).In contrast,the mean annual net biome productivity was−18.55_(−40.37)^(4.47)(−3.61),18.65_(−2.03)^(64.03)(10.29)and 24.15_(8.38)^(38.77)(24.93)Tg C year^(−1) under base-line,SWL1.5 and SWL2 modeled by the four cMIP5 ESMs.Our results indicated that the chinese grasslands would have higher productivity than the baseline and can mitigate climate change through increased C sequestration under future global warming of 1.5℃ and 2℃ with the increase of precipitation and the global increase of atmospheric CO_(2) concentration.展开更多
nhanced silicate weathering induced by the uplift of the Himalayan-Tibetan Plateau(HTP)has been considered as the major cause of pCO_(2)decline and Cenozoic cooling.However,this hypothesis remains to be validated,larg...nhanced silicate weathering induced by the uplift of the Himalayan-Tibetan Plateau(HTP)has been considered as the major cause of pCO_(2)decline and Cenozoic cooling.However,this hypothesis remains to be validated,largely due to the lack of a reliable reconstruction of the HTP weathering flux.Here,we present a 37-million-year record of the difference in the seawater radiogenic neodymium isotopic composition(△ε_(Nd))of Ocean Drilling Program(ODP)sites and Fe-Mn crusts between the northern and central Indian Ocean,which indicates the contribution of regional weathering input from the South Asian continent to the Indian Ocean.The results show a long-term increase in△ε_(Nd)and thus provide the first critical evidence of enhanced South Asian weathering input since the late Eocene.The evolution coincided well with major pulses of surface uplift in the HTP and global climatic transitions.Our foraminiferal eNd record suggests that tectonic uplift and silicate weathering in South Asia,especially in the Himalayas,might have played a significant role in the late Cenozoic cooling.展开更多
Precise and high-resolution carbon dioxide(CO_(2))emission data is of great importance in achieving carbon neutrality around the world.Here we present for the first time the near-real-time Global Gridded Daily CO_(2)E...Precise and high-resolution carbon dioxide(CO_(2))emission data is of great importance in achieving carbon neutrality around the world.Here we present for the first time the near-real-time Global Gridded Daily CO_(2)Emissions Dataset(GRACED)from fossil fuel and cement production with a global spatial resolution of 0.1°by 0.1°and a temporal resolution of 1 day.Gridded fossil emissions are computed for different sectors based on the daily national CO_(2)emissions from near-real-time dataset(Carbon Monitor),the spatial patterns of point source emission dataset Global Energy Infrastructure Emissions Database(GID),Emission Database for Global Atmospheric Research(EDGAR),and spatiotemporal patters of satellite nitrogen dioxide(NO2)retrievals.Our study on the global CO_(2)emissions responds to the growing and urgent need for high-quality,fine-grained,near-real-time CO_(2)emissions estimates to support global emissions monitoring across various spatial scales.Weshow the spatial patterns of emission changes for power,industry,residential consumption,ground transportation,domestic and international aviation,and international shipping sectors from January 1,2019,to December 31,2020.This gives thorough insights into the relative contributions from each sector.Furthermore,it provides the most up-to-date and fine-grained overview of where and when fossil CO_(2)emissions have decreased and rebounded in response to emergencies(e.g.,coronavirus disease 2019[COVID-19])and other disturbances of human activities of any previously published dataset.As the world recovers from the pandemic and decarbonizes its energy systems,regular updates of this dataset will enable policymakers to more closely monitor the effectiveness of climate and energy policies and quickly adapt.展开更多
Nitrogen oxides(NOx),significant contributors to air pollution and climate change,form aerosols and ozone in the atmosphere.Accurate,timely,and transparent information on NOx emissions is essential for decision-making...Nitrogen oxides(NOx),significant contributors to air pollution and climate change,form aerosols and ozone in the atmosphere.Accurate,timely,and transparent information on NOx emissions is essential for decision-making to mitigate both haze and ozone pollution.However,a comprehensive understanding of the trends and drivers behind anthropogenic NOx emissions from Chinadthe world's largest emitterdhas been lacking since 2020 due to delays in emissions reporting.Here we show a consistent decline in China's NOx emissions from 2020 to 2022,despite increased fossil fuel consumption,utilizing satellite observations as constraints for NOx emission estimates through atmospheric inversion.This reduction is corroborated by data from two independent spaceborne instruments:the TROPOspheric Monitoring Instrument(TROPOMI)and the Ozone Monitoring Instrument(OMI).Notably,a reduction in transport emissions,largely due to the COVID-19 lockdowns,slightly decreased China's NOx emissions in 2020.In subsequent years,2021 and 2022,reductions in NOx emissions were driven by the industry and transport sectors,influenced by stringent air pollution controls.The satellite-based inversion system developed in this study represents a significant advancement in the real-time monitoring of regional air pollution emissions from space.展开更多
The recurrent extreme El Niño events are commonly linked to reduced vegetation growth and the land carbon sink over many but discrete regions of the Northern Hemisphere(NH).However,we reported here a pervasive an...The recurrent extreme El Niño events are commonly linked to reduced vegetation growth and the land carbon sink over many but discrete regions of the Northern Hemisphere(NH).However,we reported here a pervasive and continuous vegetation greening and no weakened land carbon sink in the maturation phase of the 2015/2016 El Niño event over the NH(mainly in the extra-tropics),based on multiple evidences from remote sensing observations,global ecosystem model simulations and atmospheric CO_(2)inversions.We discovered a significant compensation effect of the enhanced vegetation growth in spring on subsequent summer/autumn vegetation growth that sustained vegetation greening and led to a slight increase in the land carbon sink over the spring and summer of 2015(average increases of 23.34%and 0.63%in net ecosystem exchange from two independent datasets relative to a 5-years average before the El Niño event,respectively)and spring of 2016(6.82%),especially in the extra-tropics of the NH,where the water supply during the pre-growing-season(November of the previous year to March of the current year)had a positive anomaly.This seasonal compensation effect was much stronger than that in 1997 and 1998 and significantly alleviated the adverse impacts of the 2015/2016 El Niño event on vegetation growth during its maturation phase.The legacy effect of water supply during the pre-growing-season on subsequent vegetation growth lasted up to approximately six months.Our findings highlight the role of seasonal compensation effects on mediating the land carbon sink in response to episodic extreme El Niño events.展开更多
A major challenge in runoff and soil erosion modelling is the adequate representation of the most relevant processes in models while avoiding over parameterization.In the European loess belt,pro-gressive soil crusting...A major challenge in runoff and soil erosion modelling is the adequate representation of the most relevant processes in models while avoiding over parameterization.In the European loess belt,pro-gressive soil crusting during rainfall events,resulting in infiltration-excess runoff,is usually considered the dominant process generating runoff on catchments covered with silty soils.Saturation-excess may also occur and affect their runoff and erosion behavior.However,saturation-excess runoff occurrence and quantification have rarely been performed and is usually not taken into account when modelling runoff and erosion in these environments.Accordingly,a continuous simulation of the Austreberthe catchment(214 km^(2)),located in the European loess belt(Normandy,France),was conducted with the new Water and Sediment(WaterSed)model over 12 years,corresponding to more than 780 individual rainfall events,at a 25 m spatial resolution.The inter-annual variability of runoff and erosion was closely linked to the number of intense events per year and their distribution through the year.The model was properly calibrated over a representative set of 35 rainfall events,considering either infiltration-excess and/or saturation-excess runoff.It was also able to reproduce the measured runoff volume for most of the monitoring period.However,the three years with most rainfall were adequately modelled only including saturation-excess runoff.An analysis performed at the seasonal scale revealed that saturation was modelled in the catchment during almost all of the modelling period,suggesting the importance of this often overlooked process in current modelling attempts.展开更多
Although alpine ecosystems have been commonly recognized as sensitive to recent climate change,few studies have examined its impact on the long-term productivity of vegetation and soil erosion.Using paleoecological re...Although alpine ecosystems have been commonly recognized as sensitive to recent climate change,few studies have examined its impact on the long-term productivity of vegetation and soil erosion.Using paleoecological records,these two aspects were examined in the alpine zone of the Taibai Mountains(elevation,3767 m)in monsoon-dominated East Asia since the middle Holocene.Proxies for the productivity of vegetation and severity of soil erosion from high-resolution alpine lacustrine records show that the productivity and soil erosion were closely related to mean annual temperature and summer precipitation from the East Asian Summer Monsoon(EASM),respectively.Specifically,when the mean annual temperature was low and precipitation was abundant,during 5800–4000 calendar years before the present(cal.yr BP),the alpine ecosystem was characterized by low vegetation productivity and severe soil erosion.However,the productivity increased and soil erosion decreased from 4000 cal.yr BP onwards.These results highlight the role of paleoecological evidence in studying ecosystem services on longer time scales,which is significant in making policies for sustainable development under climate change in regions for which such long-term monitoring data are not available.展开更多
Past assessments report negative impacts of the climate crisis in boreal areas;but milder and shorter winters and elevated atmospheric CO_(2) may provide opportunities for agricultural productivity potentially playing...Past assessments report negative impacts of the climate crisis in boreal areas;but milder and shorter winters and elevated atmospheric CO_(2) may provide opportunities for agricultural productivity potentially playing a significant role in future food security.Arable cropping systems are expanding in boreal areas,but the regional mainstay will likely continue to be livestock production.Agroecological models can when appropriately calibrated and evaluated,facilitate improved productivity while minimising environmental impacts by identifying system interactions,and quantifying greenhouse gas emissions,soil carbon stocks and fertiliser use.While models designed for temperate and tropical zones abound,few are developed specifically for boreal zones,and there is uncertainty around the performance of existing models in boreal areas.We reviewed model performance across boreal environments and management systems.We identified a dearth of modelling studies in boreal regions,with the publication of three or less papers per year since the year 2000,constituting a significant research gap.Models IFSM and BASGRA_N performed best in grassland production,DNDC best in predicting soil N_(2)O and NH_(3) emissions.No model outperformed all others,strengthening the case for ensemble modelling.Existing agroecological models would be worthy of further evaluation,providing model improvements designed for boreal systems.展开更多
The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoc...The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoch and Chibanian Stage/Age at the Chiba section,Japan.The proposal was submitted to the voting members of the International Commission on Stratigraphy’s Subcommission on Quaternary Stratigraphy(SQS)on May 4,2023,and following discussions was approved on July 8,2023.The 74 m thick IS continuously spans the Marine Isotope Stage(MIS)20–18 interval,and is part of the longer Montalbano Jonico succession(Basilicata,southern Italy in the Mediterranean region)encompassing MIS 37 to early MIS 16.The IS provides a detailed record based on multiple chronologically well constrained marine and terrestrial proxies,which are particularly useful for outlining the paleoclimatic evolution through the Lower–Middle Pleistocene transition.The high-resolution carbon and oxygen isotope stratigraphy outlines glacial–interglacial and stadial–interstadial phases as well as the sub-millennialscale features of Termination IX and the onset of MIS 19c.The sapropel layer equivalent to insolation cycle 74(784 ka)occurs in early MIS 19c.A prominent peak in the 10Be/9Be record at the MIS 19c–19b transition identifies the low geomagnetic dipole moment associated with the Matuyama–Brunhes boundary interval.Two tephra layers(V3 and V4)relevant to boundary interval are 40Ar/39Ar dated.The V4 layer,occurring at the MIS 19c–b transition and in the middle of the 10Be/9Be peak,has an age of 774.1±0.9 ka,corresponding to the age of the Middle Pleistocene GSSP.A high-resolution alkenone sea-surface temperature and several paleobiological records complement the rich chronological and paleoenvironmental dataset from MIS 20 to the inception of MIS 18.The GSSP boundary interval in the IS is represented from 35.50 to 39.50 m,which corresponds to the interval of the highest values of the 10Be/9Be ratio(~776.35–771.87 ka)and includes the V4 tephra layer and the MIS 19c–MIS 19b transition.This SABS extends the correlation potential of the Middle Pleistocene Subseries/Subepoch GSSP interval to the Mediterranean region.展开更多
文摘Particle number and mass concentrations were measured in Beijing during the winter and summer periods in 2003, together with some other parameters including black carbon (BC) and meteorological conditions. Particle mass concentrations exhibited low seasonality, and the ratio of PM2.5/PM10 in winter was higher than that in summer. Particle number size distribution (PSD) was characterized by four modes and exhibited low seasonality. BC was well correlated with the number and mass concentrations of accumulation and coarse particles, indicating these size particles are related to anthropogenic activities. Particle mass and number concentrations (except ultra-fine and nucleation particles) followed well the trends of BC concentration for the majority of the day, indicating that most particles were associated with primary emissions. The diurnal number distributions of accumulation and coarse mode particles were characterized by two peaks.
基金The National Programme on Global Change and Air-sea Interaction under contract Nos GASI-03-04-01-03 and GASI-GEOGE-03the Research Grant of Third Institute of Oceanography,State Oceanic Administration under contract No.2015015
文摘A δ^（44） Ca curve from shells of the planktonic foraminifera Globigerinoides sacculifer in calcareous biogenic oozes has been extracted from the Nintyeast Ridge in the Indian Ocean since 300 ka. By combining terrigenous inputs（e.g., grain size, magnetic susceptibility, and turbidite frequency） with the oceanic productivity（e.g., biogenic content and Neogloboquadrina dutertrei content）, it is found that the curve＇s variations are closely related to the historical evolution of the oceanic calcium cycle. The δ^（44）Ca value is in lower tendency and has small oscillation during Marine Isotope Stage（MIS） 6, when the supply of terrigenous detrital is highest. In contrast, during MIS 3,5 and 7, the δ^（44） Ca values are in higher tendency, and their fluctuations are consistent with the variations of the productivity proxies. These results suggest that the calcium isotopes are mainly influenced by the input of the Himalayan erosion products to the northern Indian Ocean. In addition, the developmental stages of calcareous planktons may have a secondary impact on the fluctuations of the calcium isotope ratio of sea water.
基金funding was provided by the Carbon Mitigation Initiative(CMI)of the Princeton Environmental Institute,and by an Oak Ridge National Lab research subcontract to A.C.C.Y.and P.C.were supported by the fire_cci project(http://www.esa-fire-cci.org/)funded by the European Space AgencyS.R.was supported by a Graduate Research Fellowship from the U.S.National Science Foundation+1 种基金R.T.,J.M.,X.S.and D.R.were supported by the Terrestrial Ecosystem Science Scientific Focus Area(TES SFA)project and the Reducing Uncertainties in Biogeochemical Interactions through Synthesis and Computing Scientific Focus Area(RUBISCO SFA)project funded by the US Department of Energy,Office of Science,Office of Biological and Environmental ResearchOak Ridge National Laboratory is supported by the Office of Science of the US Department of Energy under Contract No.DE-AC05-00OR22725.
文摘Fire is a major type of disturbance that has important influences on ecosystem dynamics and carbon cycles.Yet our understanding of ecosystem fires and their carbon cycle consequences is still limited,largely due to the difficulty of large-scale fire monitoring and the complex interactions between fire,vegetation,climate,and anthropogenic factors.Here,using data from satellite-derived fire observations and ecosystem model simulations,we performed a comprehensive investigation of the spatial and temporal dynamics of China’s ecosystem fire disturbances and their carbon emissions over the past two decades(1997–2016).Satellite-derived results showed that on average about 3.47-4.53×10^(4) km^(2) of the land was burned annually during the past two decades,among which annual burned forest area was about 0.81-1.25×10^(4) km^(2),accounting for 0.33-0.51%of the forest area in China.Biomass burning emitted about 23.02 TgC per year.Compared to satellite products,simulations from the Energy Exascale Earth System Land Model(ELM)strongly overestimated China’s burned area and fire-induced carbon emissions.Annual burned area and fire-induced carbon emissions were high for boreal forest in Northeast China’s Daxing’anling region and subtropical dry forest in South Yunnan,as revealed by both the satellite product and the model simulations.Our results suggest that climate and anthropogenic factors play critical roles in controlling the spatial and seasonal distribution of China’s ecosystem fire disturbances.Our findings highlight the importance of multiple complementary approaches in assessing ecosystem fire disturbance and its carbon consequences.Further studies are required to improve the methods of observing and modelling China’s ecosystem fire disturbances,which will provide valuable information for fire management and ecosystem sustainability in an era when both human activities and the natural environment are rapidly changing.
文摘四极杆电感耦合等离子体质谱仪(Inductively Coupled Plasma-Quadrupole Mass Spectrometry,简称ICP-QMS)可用于U和Th同位素分析。目前,ICP-QMS能实现精度大约为0.3%(U)和1%(Th)的测量分析,可提供误差在1%～10%的^(230)Th/U年代数据。本文用ICP-QMS分析了采自意大利南都Loreto旧石器地点的4颗马牙化石样品,并对已发表的UTEVA树脂提纯U和Th的流程做了进一步改进,使其适用于动物牙化石样品。样品中的U和Th含量的平均测量精度(2σ)分别为0.3%和0.6%;^(234)U/^(238)U和^(230)Th/^(238)U活度比平均精度(2σ)分别为0.3%和0.8%。数据表明同一颗牙化石的不同组织的U含量可有数量级差别,同时它们的U-Th同位素活度比也可显著地离散(>2σ),从而导致不一致的^(230)Th/U年代结果。如今测定的各牙组织的U-Th同位素数据可用于模拟U的迁移历史;U-系分析与电子自旋共振测年技术相结合或可更好地估计样品的地质年代。
文摘Work is currently underway to produce a map in Arc GISTM 10 of the mafic dyke swarms and related units(volcanics,sills and layered intrusions)of Russia and adjacent regions at a scale of 1:5,000,000.Over the past
文摘Limiting human-caused global warming to a specific level requires achieving net-zero anthropogenic carbon dioxide(CO_(2))emissions,along with strong reductions in other greenhouse gas(GHG)emissions.This means that any remaining anthropogenic CO_(2)emissions must be balanced by an equivalent amount of anthropogenic removals.
基金supported by the National Natural Science Foundation of China(42222109 and 42471429)the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0404)+1 种基金the Science and Technology Program Project of Xizang(XZ202401ZY0060)the Chinese Academy of Sciences Youth Innovation Promotion Association(2023390).
文摘Serving as the breadbasket of the Tibetan Plateau,the Middle Reach of the Yarlung Zangbo River basin is confronted withpersistentthreats of desertification,primarily driven by climate change and human activities.To address this challenge,the Chinese government has implemented afforestation initiatives in this region for over four decades,yielding substantial ecological benefits that support sustainable development.Based on extensive satellite-based observations,we reveal evidence for these positive outcomes from 1982 to 2020 and quantify their contributions.The most immediate effect is attributed to the control of desertification via restoring 59%of the sandy lands along the riverbanks and increasing forest cover from 133.85 to 419.54 km^(2).Additionally,these efforts have progressively enhanced climatic conditions by improving local heat and water conditions since 2000,despite the backdrop of global warming.This is evidenced by a decrease in land surface temperature by 2.64℃ and air temperature 0.3℃,alongside an average increase in volumetric soil moisture by 2.74%and relative humidity by 2.18%.These positive contributions significantly bolstered the region's agricultural productivity,with grain production experiencing rapid growth between 1992 and 2018.Our findings suggest that long-term afforestation efforts effectively regulate local heat and water conditions,thereby supporting sustainable socioeconomic development.
文摘尽管普遍认为高山生态系统对气候变化的响应非常敏感,但很少有研究探究气候变化对高山植被生产力和土壤侵蚀的影响.基于古生态学记录,探究了全新世中期以来处于东亚季风影响区的太白山高海拔区植被生产力和土壤侵蚀的演变.高分辨率高山湖沼记录显示,植被生产力与年平均温度密切相关,而土壤侵蚀主要受到东亚夏季风所带来的降水的影响.即在5800~4000cal. a BP期间,年平均温度较低而夏季降水充沛,高山生态系统表现为低的植被生产力且土壤侵蚀严重.但是,从4000cal. a BP开始,年平均温度升高而夏季降水减少,植被生产力显著提高且土壤侵蚀减缓.这些结果表明,古生态学记录可为研究较长时间尺度上的生态系统服务提供有力证据,可帮助制定气候变化下的生态系统可持续发展政策.
基金This work was supported by Preliminary Research on Three Poles Environment and Climate Change(2019YFC1509103)the National Natural Science Foundation of China(41861134036 and 41922004)+1 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0606)the Strategic Priority Research Program(A)of the Chinese Academy of Sciences(XDA19070303 and XDA20050101).
文摘The Tibetan Plateau(TP)and Arctic permafrost constitute two large reservoirs of organic carbon,but processes which control carbon accumulation within the surface soil layer of these areas would differ due to the interplay of climate,soil and vegetation type.Here,we synthesized currently available soil carbon data to show that mean organic carbon density in the topsoil(0-10 cm)in TP grassland(3.12±0.52 kg C m^(-2))is less than half of that in Arctic tundra(6.70±1.94 kg C m^(-2)).Such difference is primarily attributed to their difference in radiocarbon-inferred soil carbon turnover times(547 years for TP grassland versus 1609 years for Arctic tundra)rather than to their marginal difference in topsoil carbon inputs.Our findings highlight the importance of improving regional-specific soil carbon turnover and its controlling mechanisms across permafrost affected zones in ecosystem models to fully represent carbon-climate feedback.
基金supported by the Purdue University Forestry and Natural Resources research scholarship and the U. S. Forest Services contract grant to the Woods Hole Research Center
文摘Forests played an important role in carbon sequestration during the past two decades. Using a model tree ensemble method(MTE) to regress the seven reflectance bands of EOS-Terra-MODIS satellite data against country level forest biomass carbon density(BCD) of 2001–2005 provided by United Nations' s Forest Resource Assessment(FRA), we developed a global map of forest BCD at 1 km×1 km resolution for both 2001–2005 and 2006–2010. For 2006–2010, the total global forest biomass carbon stock is estimated as 279.6±7.1 Pg C, and the tropical forest biomass carbon stock is estimated as 174.4±5.4 Pg C. During the first decade of the 21 st century, we estimated an increase of global forest biomass of 0.28±0.75 Pg C yr^(-1). Tropical forest biomass carbon stock slightly decreased(-0.31±0.60 Pg C yr^(-1)); by contrast, temperate and boreal forest biomass increased(0.58±0.28 Pg C yr^(-1)) during the same period. Our estimation of the global forest biomass carbon stock and its changes is subject to uncertainties due to lack of extensive ground measurements in the tropics, spatial heterogeneity in large countries, and different definitions of forest. The continuously monitoring of forest biomass carbon stock with MODIS satellite data will provide useful information for detecting forest changes.
基金This study was supported by the National Key Research and Development Program of China(grant no.2016YFA0600202 and 2016YFC0500203)National Basic Research Program of China(grant no.2013CB956303).
文摘Aims the impacts of future global warming of 1.5℃ and 2℃ on the productivity and carbon(c)storage of grasslands in china are not clear yet,although grasslands in china support~45 million agricultural populations and more than 238 million livestock populations,and are sensitive to global warming.Methods this study used a process-based terrestrial ecosystem model named ORcHIDEE to simulate c cycle of alpine meadows and temperate grasslands in china.this model was driven by high-resolution(0.5°×0.5°)climate of global specific warming levels(SWL)of 1.5℃ and 2℃(warmer than pre-industrial level),which is downscaled by Ec-EARtH3-HR v3.1 with sea surface temperature and sea-ice concentration as boundary conditions from IPSL-cM5-LR(low spatial resolution,2.5°×1.5°)Earth system model(ESM).Important Findingscompared with baseline(1971-2005),the mean annual air temperature over chinese grasslands increased by 2.5℃ and 3.7℃ under SWL1.5 and SWL2,respectively.the increase in temperature in the alpine meadow was higher than that in the temperate grassland under both SWL1.5 and SWL2.Precipitation was also shown an increasing trend under SWL2 over most of the chinese grasslands.Strong increases in gross primary productivity(GPP)were simulated in the chinese grasslands,and the mean annual GPP(GPP_(MA))increased by 19.32%and 43.62%under SWL1.5 and SWL2,respectively.the c storage increased by 0.64 Pg c and 1.37 Pg c under SWL1.5 and SWL2 for 50 years simulations.the GPP_(MA) was 0.67_(0.39)^(0.88)(0.82)(model mean_(min) ^(max) (this study)),0.85_(0.45)^(1.24)(0.97)and 0.94_(0.61)^(1.30)(1.17)Pg C year^(−1) under baseline,SWL1.5 and SWL2 modeled by four cMIP5 ESMs(phase 5 of the coupled Model Inter-comparison Project Earth System Models).In contrast,the mean annual net biome productivity was−18.55_(−40.37)^(4.47)(−3.61),18.65_(−2.03)^(64.03)(10.29)and 24.15_(8.38)^(38.77)(24.93)Tg C year^(−1) under base-line,SWL1.5 and SWL2 modeled by the four cMIP5 ESMs.Our results indicated that the chinese grasslands would have higher productivity than the baseline and can mitigate climate change through increased C sequestration under future global warming of 1.5℃ and 2℃ with the increase of precipitation and the global increase of atmospheric CO_(2) concentration.
文摘nhanced silicate weathering induced by the uplift of the Himalayan-Tibetan Plateau(HTP)has been considered as the major cause of pCO_(2)decline and Cenozoic cooling.However,this hypothesis remains to be validated,largely due to the lack of a reliable reconstruction of the HTP weathering flux.Here,we present a 37-million-year record of the difference in the seawater radiogenic neodymium isotopic composition(△ε_(Nd))of Ocean Drilling Program(ODP)sites and Fe-Mn crusts between the northern and central Indian Ocean,which indicates the contribution of regional weathering input from the South Asian continent to the Indian Ocean.The results show a long-term increase in△ε_(Nd)and thus provide the first critical evidence of enhanced South Asian weathering input since the late Eocene.The evolution coincided well with major pulses of surface uplift in the HTP and global climatic transitions.Our foraminiferal eNd record suggests that tectonic uplift and silicate weathering in South Asia,especially in the Himalayas,might have played a significant role in the late Cenozoic cooling.
基金the National Natural Science Foundation of China(grants 41921005 and 71874097)Beijing Natural Science Foundation(JQ19032)the Qiu Shi Science&Technologies Foundation.
文摘Precise and high-resolution carbon dioxide(CO_(2))emission data is of great importance in achieving carbon neutrality around the world.Here we present for the first time the near-real-time Global Gridded Daily CO_(2)Emissions Dataset(GRACED)from fossil fuel and cement production with a global spatial resolution of 0.1°by 0.1°and a temporal resolution of 1 day.Gridded fossil emissions are computed for different sectors based on the daily national CO_(2)emissions from near-real-time dataset(Carbon Monitor),the spatial patterns of point source emission dataset Global Energy Infrastructure Emissions Database(GID),Emission Database for Global Atmospheric Research(EDGAR),and spatiotemporal patters of satellite nitrogen dioxide(NO2)retrievals.Our study on the global CO_(2)emissions responds to the growing and urgent need for high-quality,fine-grained,near-real-time CO_(2)emissions estimates to support global emissions monitoring across various spatial scales.Weshow the spatial patterns of emission changes for power,industry,residential consumption,ground transportation,domestic and international aviation,and international shipping sectors from January 1,2019,to December 31,2020.This gives thorough insights into the relative contributions from each sector.Furthermore,it provides the most up-to-date and fine-grained overview of where and when fossil CO_(2)emissions have decreased and rebounded in response to emergencies(e.g.,coronavirus disease 2019[COVID-19])and other disturbances of human activities of any previously published dataset.As the world recovers from the pandemic and decarbonizes its energy systems,regular updates of this dataset will enable policymakers to more closely monitor the effectiveness of climate and energy policies and quickly adapt.
基金supported by the National Key R&D Program of China(Grant No.2021YFB3901000)the National Natural Science Foundation of China(Grant No.42105094)the Shenzhen Science,Technology and Innovation Commission(Grant No.WDZC20220810110301001).
文摘Nitrogen oxides(NOx),significant contributors to air pollution and climate change,form aerosols and ozone in the atmosphere.Accurate,timely,and transparent information on NOx emissions is essential for decision-making to mitigate both haze and ozone pollution.However,a comprehensive understanding of the trends and drivers behind anthropogenic NOx emissions from Chinadthe world's largest emitterdhas been lacking since 2020 due to delays in emissions reporting.Here we show a consistent decline in China's NOx emissions from 2020 to 2022,despite increased fossil fuel consumption,utilizing satellite observations as constraints for NOx emission estimates through atmospheric inversion.This reduction is corroborated by data from two independent spaceborne instruments:the TROPOspheric Monitoring Instrument(TROPOMI)and the Ozone Monitoring Instrument(OMI).Notably,a reduction in transport emissions,largely due to the COVID-19 lockdowns,slightly decreased China's NOx emissions in 2020.In subsequent years,2021 and 2022,reductions in NOx emissions were driven by the industry and transport sectors,influenced by stringent air pollution controls.The satellite-based inversion system developed in this study represents a significant advancement in the real-time monitoring of regional air pollution emissions from space.
基金This study was financially supported by the National Key Research and Development Program of China(Grant No.2022YFF0801802)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0306)+2 种基金the National Natural Science Foundation of China(Grant No.42171050)the China Postdoctoral Science Foundation(Grant No.2023M730281)the State Key Laboratory of Earth Surface Processes and Resource Ecology of Beijing Normal University(Grant No.2023-KF-07).
文摘The recurrent extreme El Niño events are commonly linked to reduced vegetation growth and the land carbon sink over many but discrete regions of the Northern Hemisphere(NH).However,we reported here a pervasive and continuous vegetation greening and no weakened land carbon sink in the maturation phase of the 2015/2016 El Niño event over the NH(mainly in the extra-tropics),based on multiple evidences from remote sensing observations,global ecosystem model simulations and atmospheric CO_(2)inversions.We discovered a significant compensation effect of the enhanced vegetation growth in spring on subsequent summer/autumn vegetation growth that sustained vegetation greening and led to a slight increase in the land carbon sink over the spring and summer of 2015(average increases of 23.34%and 0.63%in net ecosystem exchange from two independent datasets relative to a 5-years average before the El Niño event,respectively)and spring of 2016(6.82%),especially in the extra-tropics of the NH,where the water supply during the pre-growing-season(November of the previous year to March of the current year)had a positive anomaly.This seasonal compensation effect was much stronger than that in 1997 and 1998 and significantly alleviated the adverse impacts of the 2015/2016 El Niño event on vegetation growth during its maturation phase.The legacy effect of water supply during the pre-growing-season on subsequent vegetation growth lasted up to approximately six months.Our findings highlight the role of seasonal compensation effects on mediating the land carbon sink in response to episodic extreme El Niño events.
基金This research was funded by the AMORAD(ANR-11-RSNR-0002)project(Agence Nationale de la Recherche,Programme des Inves-tissements d'Avenir).This work was also supported by the ANR project"RICOCHET:Multi-risk assessment on coastal territory in a global change context(2017-2021)"(ANR-16-CE03-0008).
文摘A major challenge in runoff and soil erosion modelling is the adequate representation of the most relevant processes in models while avoiding over parameterization.In the European loess belt,pro-gressive soil crusting during rainfall events,resulting in infiltration-excess runoff,is usually considered the dominant process generating runoff on catchments covered with silty soils.Saturation-excess may also occur and affect their runoff and erosion behavior.However,saturation-excess runoff occurrence and quantification have rarely been performed and is usually not taken into account when modelling runoff and erosion in these environments.Accordingly,a continuous simulation of the Austreberthe catchment(214 km^(2)),located in the European loess belt(Normandy,France),was conducted with the new Water and Sediment(WaterSed)model over 12 years,corresponding to more than 780 individual rainfall events,at a 25 m spatial resolution.The inter-annual variability of runoff and erosion was closely linked to the number of intense events per year and their distribution through the year.The model was properly calibrated over a representative set of 35 rainfall events,considering either infiltration-excess and/or saturation-excess runoff.It was also able to reproduce the measured runoff volume for most of the monitoring period.However,the three years with most rainfall were adequately modelled only including saturation-excess runoff.An analysis performed at the seasonal scale revealed that saturation was modelled in the catchment during almost all of the modelling period,suggesting the importance of this often overlooked process in current modelling attempts.
基金supported by the National Natural Science Foundation of China(Grant Nos.41901092,41171160)the Fundamental Research Funds for the Central Universities of China(Grant No.GK202003069).
文摘Although alpine ecosystems have been commonly recognized as sensitive to recent climate change,few studies have examined its impact on the long-term productivity of vegetation and soil erosion.Using paleoecological records,these two aspects were examined in the alpine zone of the Taibai Mountains(elevation,3767 m)in monsoon-dominated East Asia since the middle Holocene.Proxies for the productivity of vegetation and severity of soil erosion from high-resolution alpine lacustrine records show that the productivity and soil erosion were closely related to mean annual temperature and summer precipitation from the East Asian Summer Monsoon(EASM),respectively.Specifically,when the mean annual temperature was low and precipitation was abundant,during 5800–4000 calendar years before the present(cal.yr BP),the alpine ecosystem was characterized by low vegetation productivity and severe soil erosion.However,the productivity increased and soil erosion decreased from 4000 cal.yr BP onwards.These results highlight the role of paleoecological evidence in studying ecosystem services on longer time scales,which is significant in making policies for sustainable development under climate change in regions for which such long-term monitoring data are not available.
基金supported by funding from the Ministry of Agriculture and Forestry Finland(Helsinki,FI)(Project:Clover for biogas,Project NC-GRASS:VN/28562/2020-MMM-2)the support from the Academy of Finland funded ENSINK project(Decision number 334422).
文摘Past assessments report negative impacts of the climate crisis in boreal areas;but milder and shorter winters and elevated atmospheric CO_(2) may provide opportunities for agricultural productivity potentially playing a significant role in future food security.Arable cropping systems are expanding in boreal areas,but the regional mainstay will likely continue to be livestock production.Agroecological models can when appropriately calibrated and evaluated,facilitate improved productivity while minimising environmental impacts by identifying system interactions,and quantifying greenhouse gas emissions,soil carbon stocks and fertiliser use.While models designed for temperate and tropical zones abound,few are developed specifically for boreal zones,and there is uncertainty around the performance of existing models in boreal areas.We reviewed model performance across boreal environments and management systems.We identified a dearth of modelling studies in boreal regions,with the publication of three or less papers per year since the year 2000,constituting a significant research gap.Models IFSM and BASGRA_N performed best in grassland production,DNDC best in predicting soil N_(2)O and NH_(3) emissions.No model outperformed all others,strengthening the case for ensemble modelling.Existing agroecological models would be worthy of further evaluation,providing model improvements designed for boreal systems.
文摘The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoch and Chibanian Stage/Age at the Chiba section,Japan.The proposal was submitted to the voting members of the International Commission on Stratigraphy’s Subcommission on Quaternary Stratigraphy(SQS)on May 4,2023,and following discussions was approved on July 8,2023.The 74 m thick IS continuously spans the Marine Isotope Stage(MIS)20–18 interval,and is part of the longer Montalbano Jonico succession(Basilicata,southern Italy in the Mediterranean region)encompassing MIS 37 to early MIS 16.The IS provides a detailed record based on multiple chronologically well constrained marine and terrestrial proxies,which are particularly useful for outlining the paleoclimatic evolution through the Lower–Middle Pleistocene transition.The high-resolution carbon and oxygen isotope stratigraphy outlines glacial–interglacial and stadial–interstadial phases as well as the sub-millennialscale features of Termination IX and the onset of MIS 19c.The sapropel layer equivalent to insolation cycle 74(784 ka)occurs in early MIS 19c.A prominent peak in the 10Be/9Be record at the MIS 19c–19b transition identifies the low geomagnetic dipole moment associated with the Matuyama–Brunhes boundary interval.Two tephra layers(V3 and V4)relevant to boundary interval are 40Ar/39Ar dated.The V4 layer,occurring at the MIS 19c–b transition and in the middle of the 10Be/9Be peak,has an age of 774.1±0.9 ka,corresponding to the age of the Middle Pleistocene GSSP.A high-resolution alkenone sea-surface temperature and several paleobiological records complement the rich chronological and paleoenvironmental dataset from MIS 20 to the inception of MIS 18.The GSSP boundary interval in the IS is represented from 35.50 to 39.50 m,which corresponds to the interval of the highest values of the 10Be/9Be ratio(~776.35–771.87 ka)and includes the V4 tephra layer and the MIS 19c–MIS 19b transition.This SABS extends the correlation potential of the Middle Pleistocene Subseries/Subepoch GSSP interval to the Mediterranean region.
