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Improving the quantification of waterfowl migration with remote sensing and bird tracking

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Science Bulletin 2015年第23期60卷 1984-1993页

作者： Yali Si Qinchuan Xin Herbert H.T.Prins Willem f.de Boer Peng Gong ministry of education key laboratory for earth system modeling Center for Earth System Science Tsinghua University Joint Center for Global Change Studies Resource Ecology Group Wageningen University

Accurately quantifying waterfowl migration patterns is pertinent to monitor ecosystem health and control bird-borne infectious diseases. In this review, we summarize the current understanding of the environmental mechanisms that drive waterfowl migration and then investigate the effect of intra- and inter-annual change in food supply and temperature(e.g., climate change) on their migration patterns. Recent advances in remote sensing and animal tracking techniques make it possible to monitor these environmental factors over a wide range of scales and record bird movements in detail. The synergy of these techniques will facilitate substantial progress in our understanding of the environmental drivers of bird migration. We identify prospects for future studies to test existing hypotheses and develop models integrating up-todate knowledge, high-resolution remote sensing data and high-accuracy bird tracking data. This will allow us to predict when waterfowl will be where, in response to shortand long-term global environmental change.

关键词： Waterfowl migration · Environmentaldrivers · Phenology · Stopover ·Remote sensing ·Bird tracking

A study on coupling technique and implementation of the wave-circulation coupled model

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High Technology Letters 2014年第1期20卷 82-87页

作者：张志远 Liu Li Zhou Yufeng Zhang Cheng Li Ruizhe Chen Yushu Song Guojie Yang Guangwen Department of Computer Science and Technology Tsinghua University ministry of education key laboratory for earth system modeling Center for Earth System ScienceTsinghua University Hydro-Meteorological Center of Navy

The coupler is fundamental for a coupled model to realize complex interactions among component *** paper focuses on the coupling process of Wave-Circulation(W-C) coupled model which consists of MASNUM(key laboratory of marine science and numerical modeling wave model)and PoM(Princeton ocean Model).The current coupling module of this coupled model is based on the inefficient I/o file,which has already become a performance bottleneck especially when the coupled model utilizes a large number of *** improve the performance of the W-C model,a flexible coupling module based on the model coupling toolkit(MCT) is designed and implemented to replace the current I/o file coupling module in the coupled *** studies that we have carried out demonstrate that our online coupling module can dramatically improve the parallel performance of the coupled *** online coupling module outperforms the I/o file coupling *** processes increase to 96,the whole process of EXP-C takes only 695.8 seconds,which is only 58.8%of the execution time of *** on our experiments under 2D Parallel Decomposition(2DPD),we suggest setting parallel decomposition strategies automatically to component models in order to achieve high parallel efficiency.

关键词： coupling technique model coupling toolkit (MCT) W-C coupled online cou-pling module 2D Parallel Decomposition (2DPD) parallel performance

Pressure gradient errors in a covariant method of implementing theσ-coordinate:idealized experiments and geometric analysis

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Atmospheric and oceanic Science Letters 2016年第4期9卷 270-276页

作者： LI Jin-Xi LI Yi-Yuan WANG Bin State key laboratory of Numerical modeling for Atmospheric Sciences and Geophysical fluid Dynamics institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of earth Science University of Chinese Academy of SciencesBeijingChina ministry of education key laboratory for earth system modeling and Center for Earth System ScienceTsinghua UniversityBeijingChina

A new approach is proposed to use the covariant scalar equations of the a-coordinate （the covariant method）, in which the pressure gradient force （PGf） has only one term in each horizontal momentum equation, and the PGf errors are much reduced in the computational space. In addition, the validity of reducing the PGf errors by this covariant method in the computational and physical space over steep terrain is investigated. first, the authors implement a set of idealized experiments of increasing terrain slope to compare the PGf errors of the covariant method and those of the classic method in the computational space. The results demonstrate that the PGf errors of the covariant method are consistently much-reduced, compared to those of the classic method. More importantly, the steeper the terrain, the greater the reduction in the ratio of the PGf errors via the covariant method. Next, the authors use geometric analysis to further investigate the PGf errors in the physical space, and the results illustrates that the PGf of the covariant method equals that of the classic method in the physical space; namely, the covariant method based on the non-orthogonal a-coordinate cannot reduce the PGf errors in the physical space. However, an orthogonal method can reduce the PGf errors in the physical space. finally, a set of idealized experiments are carried out to validate the results obtained by the geometric analysis. These results indicate that the covariant method may improve the simulation of variables relevant to pressure, in addition to pressure itself, near steep terrain.

关键词： Pressure gradient forceerrors covariant scalarequations of the o-coordinate steep terrain computational andphysical space geometricanalysis non-orthogonala-coordinate

Air pollution characteristics and their relationship with emissions and meteorology in the Yangtze River Delta region during 2014–2016

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Journal of Environmental Sciences 2019年第9期31卷 8-20页

作者： Tao Ma fengkui Duan Kebin He Yu Qin Dan Tong Guannan Geng Xuyan Liu Hui Li Shuo Yang Siqi Ye Beiyao Xu Qiang Zhang Yongliang Ma State key Joint laboratory of Environment Simulation and Pollution Control School of Environment State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Tsinghua University Beijing 100084 China ministry of education key laboratory for earth system modeling Department of Earth System Science Tsinghua University Beijing 100084 China National Satellite Meteorological Center Beijing 100081 China College of Resources and Environmental Sciences China Agricultural University Beijing 100094 China

With rapid economic growth and urbanization, the Yangtze River Delta(YRD) region in China has experienced serious air pollution challenges. In this study, we analyzed the air pollution characteristics and their relationship with emissions and meteorology in the YRD region during 2014–2016. In recent years, the concentrations of all air pollutants, except o3,decreased. Spatially, the PM2.5, PM10, So2, and Co concentrations were higher in the northern YRD region, and No2 and o3 were higher in the central YRD region. Based on the number of non-attainment days(i.e., days with air quality index greater than 100), PM2.5 was the largest contributor to air pollution in the YRD region, followed by o3, PM10, and ***, particulate matter pollution has declined gradually, while o3 pollution *** conditions mainly influenced day-to-day variations in pollutant concentrations. PM2.5 concentration was inversely related to wind speed, while o3 concentration was positively correlated with temperature and negatively correlated with relative *** air quality improvement in recent years was mainly attributed to emission *** 2014–2016, PM2.5, PM10, So2, Nox, Co, NH3, and volatile organic compound(VoC)emissions in the YRD region were reduced by 26.3%, 29.2%, 32.4%, 8.1%, 15.9%, 4.5%, and0.3%, respectively. Regional transport also contributed to the air pollution. During regional haze periods, pollutants from North China and East China aggravated the pollution in the YRD region. our findings suggest that emission reduction and regional joint prevention and control helped to improve the air quality in the YRD region.

关键词： Air pollution Spatiotemporal variation Meteorological condition Emission inventory Regional transport Yangtze River Delta

on the timing of the East Asian summer monsoon maximum during the Holocene—Does the speleothem oxygen isotope record reflect monsoon rainfall variability?

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Science China earth Sciences 2016年第12期59卷 2328-2338页

作者： CHEN JianHui RAo ZhiGuo LIU JianBao HUANG Wei fENG Song DoNG GuangHui HU Yu XU QingHai CHEN faHu key laboratory of West China s Environmental system(ministry of education) College of Earth and Environmental SciencesLanzhou University Department of Geosciences University of Arkansas Institute of Nihewan Archaeology Research Hebei Normal University

The evolution of the East Asian summer monsoon(EASM) during the Holocene has long been of significant *** of past EASM variability not only increases our understanding of monsoon dynamics on a long timescale,but it also provides an environmental and climatic background for research into Chinese cultural ***,the timing of the EASM maximum remains *** popular concept of an "early Holocene maximum" is mainly based on speleothemδ18o(δ18oc) records from caves in southern China;however,the interpretation of δ18oCas a reliable proxy for EASM intensity is being increasingly *** present paper is a critical review of the climatic significance of the δ18oCrecord from ***,we suggest that precipitation in northern China is an appropriate index of EASM intensity,the variation of which clearly indicates a mid-Holocene monsoon ***,an interregional comparison demonstrates that the precipitation record in northern China is quite different from that in southern China on a range of timescales,and is inconsistent with the spatial similarity exhibited by speleothem oxygen isotope ***,both modeling and observational data show that the δ18oCrecords from southern China indeed reflect changes in precipitation δ18o(δ18oP) rather than precipitation amount,and therefore that their use as an EASM proxy is ***,we address several significant monsoon-related issues-including the driving mechanism of the EASM on an orbital timescale,the climatic significance of speleothem oxygen isotopes,and the relationship between atmospheric circulation and precipitation in monsoonal regions.

关键词： East Asian summer monsoon Holocene Speleothem oxygen isotopes

New WHo global air quality guidelines help prevent premature deaths in China

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National Science Review 2022年第4期9卷 10-12页

作者： Tao Xue Guannan Geng Xia Meng Qingyang Xiao Yixuan Zheng Jicheng Gong Jun Liu Wei Wan Qiang Zhang Haidong Kan Shiqiu Zhang Tong Zhu Institute of Reproductive and Child Health/National Health Commission key laboratory of Reproductive Health and Department of Epidemiology and Biostatistics School of Public HealthPeking University State key Joint laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua University School of Public Health Key Laboratory of Public Health Safety of the Ministry of Educationand Key Laboratory of Health Technology Assessment of the Ministry of HealthFudan University Center of Air Quality Simulation and system Analysis Chinese Academy of Environmental Planning College of Environmental Sciences and Engineering Peking University School of Energy and Environmental Engineering University of Science and Technology Beijing Clean Air Asia ministry of education key laboratory for earth system modeling Department of Earth System ScienceTsinghua University

The air quality guidelines (AQGs) issued by the World Health organization (WHo) in 2005 are key references for the National Ambient Air Quality Standards (NAAQSs) in *** 22September 2021,the WHo issued new AQGs (NAQGs)[1],which propose more stringent targets to control exposure to multiple air pollutants,including fine particulate matter (PM2.5) and ozone (o3),to which,in 2019,451 million premature deaths,globally,were attributable [2].

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The impact of ocean data assimilation on seasonal predictions based on the National Climate Center climate system model

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Acta oceanologica Sinica 2021年第5期40卷 58-70页

作者： Wei Zhou Jinghui Li fanghua Xu Yeqiang Shu Yang feng Equipment Public Service Center South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong laboratory(Guangzhou) Guangzhou 511458China ministry of education key laboratory for earth system modeling Department of Earth System ScienceTsinghua UniversityBeijing 100084China State key laboratory of Tropical oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China

An ensemble optimal interpolation(EnoI)data assimilation method is applied in the BCCCSM1.1 to investigate the impact of ocean data assimilations on seasonal forecasts in an idealized twin experiment *** of sea surface temperature(SST),sea surface height(SSH),sea surface salinity(SSS),temperature and salinity(T/S)profiles were first generated in a free model ***,a series of sensitivity tests initialized with predefined bias were conducted for a one-year period;this involved a free run(CTR)and seven assimilation *** tests allowed us to check the analysis field accuracy against the"truth".As expected,data assimilation improved all investigated quantities;the joint assimilation of all variables gave more improved results than assimilating them ***-year predictions initialized from the seven runs and CTR were then conducted and *** forecasts initialized from joint assimilation of surface data produced comparable SST root mean square errors to that from assimilation of T/S profiles,but the assimilation of T/S profiles is crucial to reduce subsurface *** ocean surface currents in the tropics were better predicted when initial conditions produced by assimilating T/S profiles,while surface data assimilation became more important at higher latitudes,particularly near the western boundary *** predictions of ocean heat content and mixed layer depth are significantly improved initialized from the joint assimilation of all the ***,a central Pacific El Ni?o was well predicted from the joint assimilation of surface data,indicating the importance of joint assimilation of SST,SSH,and SSS for ENSo predictions.

关键词： global ocean data assimilation EnoI twin experiments

Local temperature and El Niño Southern oscillation influence migration phenology of East Asian migratory waterbirds wintering in Poyang,China

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Integrative Zoology 2017年第4期12卷 303-317页

作者： fei XU Guanhua LIU Yali SI ministry of education key laboratory for earth system modeling Department of Earth System ScienceTsinghua UniversityBeijingChina Jiangxi Poyang Lake National Nature Reserve Authority Jiangxi Poyang Lake Wetland Ecosystem National Research StationNanchangChina Resource Ecology Group Wageningen UniversityWageningenthe Netherlands Center for Tropical Research Institute of the Environment and SustainabilityUniversity of CaliforniaLos AngelesCaliforniaUSA

Temperature is a critical factor influencing avian phenology,due to its direct impact on food and water *** previous studies have focused on the timing of spring migration and the arrival of birds at breeding grounds along the European and American flyways;little is known about migration ecology at the wintering sites along the Asian *** linear regression models,this study investigates how local temperature variation and EI Niño Southern oscillation(ENSo)influences the arrival and departure timing of 9 waterbird species breeding in Mongolia or Siberia and overwintering in Poyang,China from 2002 to *** mainly arrive at Poyang in october and depart for their breeding sites in *** of the 9 species,6 show a strong negative relationship between departure time and overwintering temperature in *** dates also show a negative association with overwintering ENSo and March ENSo for two *** local and large-scale climate indices show no influence on the arrival timing of *** suggest that birds react to the annual variation of overwintering temperature:an earlier departure of waterbirds is facilitated by a warmer overwintering period and vice *** long-term accumulated temperature effect is more pronounced than ENSo and the short-term local temperature *** findings could help quantify the potential impact of global warming on waterbirds.

关键词： annual temperature variation arrival and departure time ENSo local accumulated temperature overwintering birds

Methane and nitrous oxide emissions from municipal wastewater treatment plants in China:A plant-level and technology-specific study

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Environmental Science and Ecotechnology 2024年第4期20卷 123-130页

作者： Haiyan Li Liangfang You He Du Bowen Yu Lu Lu Bo Zheng Qiang Zhang Kebin He Nanqi Ren School of Civil and Environmental Engineering Harbin Institute of TechnologyShenzhen518055China Shenzhen key laboratory of Ecological Remediation and Carbon Sequestration Institute of Environment and EcologyTsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055China ministry of education key laboratory for earth system modeling Department of Earth System ScienceTsinghua UniversityBeijing100084China State key Joint laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China

Wastewater treatment is an important source of greenhouse gases(GHGs).Yet large uncertainties remain in the quantification of GHG emissions from municipal wastewater treatment plants(MWWTPs)in China.A high-resolution and technology-specific emission inventory is still lacking to support mitigation strategies of *** we develop a plant-level and technology-based MWWTP emission inventory for China covering 8703 plants and 19 treatment technology categories by compiling and harmonizing the most up-to-date facility-level ***'s methane(CH_(4))and nitrous oxide(N_(2)o)emissions from MWWTPs in 2020 are estimated to be 150.6 Gg and 22.0 Gg,respectively,with the uncertainty range of-30%to 37%and-30%to 26%at 95%confidence *** find an emission inequality across cities,with the richest cities emitting two times more CH_(4)and N_(2)o per capita from municipal wastewater treatment than the poorest *** emitted CH_(4)and N_(2)o are dominated by Anaerobic/Anoxic/oxic-,Sequencing Batch Reactor-,oxidation Ditch-,and Anoxic/oxic-based MWWTPs of less than 20 years *** the relatively young age structure of China's MWWTPs,the committed emissions highlight the importance of reducing on-site GHG emissions by optimization of operating conditions and innovation *** emission differences among our estimates,previous studies,and the Intergovernmental Panel on Climate Change guidelines are largely attributed to the uncertainties in emission factors,implying the urgent need for more plant-integrated measurements to improve the accuracy of emission accounting.

关键词： Methane Nitrous oxide Emissions Municipal wastewater treatment plants