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An Initial Perturbation Method for the Multiscale Singular Vector in Global Ensemble Prediction

Advances in Atmospheric Sciences 2024年第3期41卷 545-563页

作者： Xin LIU Jing CHEN Yongzhu LIU Zhenhua HUO zhizhen xu Fajing CHEN Jing WANG Yanan MA Yumeng HAN School of Atmospheric Sciences Nanjing University of Information Science&TechnologyNanjing 210044China Chinese Academy of Meteorological Sciences Beijing 100081China CMA Earth System Modeling and Prediction Centre(CEMC) Beijing 100081China Key Laboratory of Earth System Modeling and Prediction of China Meteorological Administration Beijing 100081China Tianjin Meteorological Observatory Tianjin 300074China China Meteorological Administration Xiong’an Atmospheric Boundary Layer Key Laboratory Hebei 071799China

Ensemble prediction is widely used to represent the uncertainty of single deterministic Numerical Weather Prediction(NWP) caused by errors in initial conditions(ICs). The traditional Singular Vector(SV) initial perturbation method tends only to capture synoptic scale initial uncertainty rather than mesoscale uncertainty in global ensemble prediction. To address this issue, a multiscale SV initial perturbation method based on the China Meteorological Administration Global Ensemble Prediction System(CMA-GEPS) is proposed to quantify multiscale initial uncertainty. The multiscale SV initial perturbation approach entails calculating multiscale SVs at different resolutions with multiple linearized physical processes to capture fast-growing perturbations from mesoscale to synoptic scale in target areas and combining these SVs by using a Gaussian sampling method with amplitude coefficients to generate initial perturbations. Following that, the energy norm,energy spectrum, and structure of multiscale SVs and their impact on GEPS are analyzed based on a batch experiment in different seasons. The results show that the multiscale SV initial perturbations can possess more energy and capture more mesoscale uncertainties than the traditional single-SV method. Meanwhile, multiscale SV initial perturbations can reflect the strongest dynamical instability in target areas. Their performances in global ensemble prediction when compared to single-scale SVs are shown to(i) improve the relationship between the ensemble spread and the root-mean-square error and(ii) provide a better probability forecast skill for atmospheric circulation during the late forecast period and for short-to medium-range precipitation. This study provides scientific evidence and application foundations for the design and development of a multiscale SV initial perturbation method for the GEPS.

关键词： multiscale uncertainty singular vector initial perturbation global ensemble prediction system

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基于SRP模型的柴达木盆地生态脆弱性评价

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盐湖研究 2024年第3期32卷 53-60页

作者：徐至真王建萍韩积斌中国科学院青海盐湖研究所中国科学院盐湖资源综合高效利用重点实验室青海西宁810008 青海省盐湖地质与环境重点实验室青海西宁810008 中国科学院大学北京100049

生态脆弱性评价是生态治理和修复的重要前提。柴达木盆地是对全球气候变化和人类活动干扰最为敏感的区域之一。通过SRP模型构建柴达木盆地生态脆弱性评价指标体系,基于地理信息技术和遥感技术,采用层次分析法,系统、定量地对柴达木盆地... 详细信息

生态脆弱性评价是生态治理和修复的重要前提。柴达木盆地是对全球气候变化和人类活动干扰最为敏感的区域之一。通过SRP模型构建柴达木盆地生态脆弱性评价指标体系,基于地理信息技术和遥感技术,采用层次分析法,系统、定量地对柴达木盆地生态脆弱性进行评价。结果表明:1)柴达木盆地微度,轻度类型脆弱区面积为79326 km^(2),占区域总面积的29.28%;中度类型脆弱区面积为67044 km^(2),占区域总面积的24.74%;重度,极度类型脆弱区面积为124613 km^(2),占区域总面积的45.98%。2)柴达木盆地东中西部生态脆弱性表现为“低-中-高”的分布特征。3)柴达木盆地生态脆弱性呈现出强烈的空间正相关特征。

关键词： SRP模型生态脆弱性柴达木盆地空间自相关

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A Nonlinear Representation of Model Uncertainty in a Convective-Scale Ensemble Prediction System

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Advances in Atmospheric Sciences 2022年第9期39卷 1432-1450页

作者： zhizhen xu Jing CHEN Mu MU Guokun DAI Yanan MA Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China Numerical Weather Prediction Center China Meteorological AdministrationBeijing 100081China Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081China

How to accurately address model uncertainties with consideration of the rapid nonlinear error growth characteristics in a convection-allowing system is a crucial issue for performing convection-scale ensemble *** this study,a new nonlinear model perturbation technique for convective-scale ensemble forecasts is developed to consider a nonlinear representation of model errors in the Global and Regional Assimilation and Prediction Enhanced System(GRAPES)Convection-Allowing Ensemble Prediction System(CAEPS).The nonlinear forcing singular vector(NFSV)approach,that is,conditional nonlinear optimal perturbation-forcing(CNOP-F),is applied in this study,to construct a nonlinear model perturbation method for *** experiments are performed:One of them is the CTL experiment,without adding any model perturbation;the other two are NFSV-perturbed experiments,which are perturbed by NFSV with two different groups of constraint radii to test the sensitivity of the perturbation magnitude *** results show that the NFSV-perturbed experiments achieve an overall improvement and produce more skillful forecasts compared to the CTL experiment,which indicates that the nonlinear NFSV-perturbed method can be used as an effective model perturbation method for convection-scale ensemble ***,the NFSV-L experiment with large perturbation constraints generally performs better than the NFSV-S experiment with small perturbation constraints in the verification for upper-air and surface weather *** for precipitation verification,the NFSV-S experiment performs better in forecasts for light precipitation,and the NFSV-L experiment performs better in forecasts for heavier precipitation,indicating that for different precipitation events,the perturbation magnitude constraint must be carefully *** the findings above lay a foundation for the design of nonlinear model perturbation methods for future CAEPSs.

关键词： Convection-Allowing Ensemble Prediction System model uncertainty nonlinear forcing singular vector

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中美工作场所空气中氨的标准检测方法比较及启示

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安全 2024年第1期45卷 37-43页

作者：许志珍郭玲王昱付朝晖舒木水北京市科学技术研究院城市安全与环境科学研究所北京100054 北京城市学院北京100083

为解决国内现行的工作场所空气中氨的标准检测方法(吸收液采集——纳氏试剂分光光度法)在实际应用中暴露出的问题,通过文献分析,梳理中美工作场所空气中氨的检测方法的发展历程,对比分析中美该标准检测方法的优缺点,为我国标准检测方法... 详细信息

为解决国内现行的工作场所空气中氨的标准检测方法(吸收液采集——纳氏试剂分光光度法)在实际应用中暴露出的问题,通过文献分析,梳理中美工作场所空气中氨的检测方法的发展历程,对比分析中美该标准检测方法的优缺点,为我国标准检测方法的更新提供启示和借鉴。研究表明:国内对于工作场所空气中氨的采样方法和测定方法(吸收液采集——纳氏试剂分光光度法)存在不宜长距离携带、不适用于个体采样、样品稳定性差、使用剧毒试剂和操作繁琐等缺点;对于固体吸附剂管,目前国内市售的存在杂质元素背景较高、采样性能和稳定性较差等缺点,不适用于空气中氨的采集,国外市售的对于企业定期进行职业卫生评价和检测存在成本较高的问题。因此需开发适用于我国工作场所空气中氨采集的固体吸附剂管,有益于推动工作场所空气中氨采集的标准方法的更新,为企业及职业卫生评价和检测人员提供工作便利。

关键词：工作场所氨离子色谱法标准测定方法

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电感耦合等离子发射光谱法测量纺织品中镉、铅含量的不确定度评定

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纺织报告 2024年第07期43卷 1-4页

作者：窦妍舒木水王昱丁玎纪晓慧许志珍郭玲北京市科学技术研究院城市安全与环境科学研究所

为了评估实验室使用电感耦合等离子发射光谱法测量纺织品中总镉及总铅含量测试结果的不确定度，依照GB/T30157—2013《纺织品总铅和总镉含量的测定》、CNAS-TR L-002《纺织品检测测量不确定度的评估及实例》方法要求对纺织品样品中总镉... 详细信息

为了评估实验室使用电感耦合等离子发射光谱法测量纺织品中总镉及总铅含量测试结果的不确定度，依照GB/T30157—2013《纺织品总铅和总镉含量的测定》、CNAS-TR L-002《纺织品检测测量不确定度的评估及实例》方法要求对纺织品样品中总镉、总铅含量进行测量，创建数学模型。文章对整个测量过程中各个影响不确定度的分量进行分析，得出纺织品中金属镉、铅含量测量的不确定度主要影响因素为标准曲线配制引起的不确定度和随机效应引起的不确定度，为纺织品检测人员对金属镉、铅的测定提供了参考。

关键词：不确定度金属镉金属铅纺织品

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Study on the effects of organic matter characteristics on the residual aluminum and flocs in coagulation processes

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Journal of Environmental Sciences 2018年第1期30卷 307-317页

作者： Hui xu Dawei Zhang zhizhen xu Yanjing Liu Ruyuan Jiao Dongsheng Wang Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China. State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China School of Environmental and Municipal Engineering Xi'an University of Architecture and TechnologyXi'an 710055China Key Laboratory of Occupational Safety and Health.Beijing Municipai Institute of Labor Protection B-eijing 100054China College of Life Science and Bio-engineering Beijing University of TechnologyBeijing 100224China

Characteristics of organic matter may affect the residual aluminum after the coagulation process. This study reported the results of a survey for one drinking water treatment plant and measured the concentration of residual aluminum species with different molecular *** results indicated that humic acid or organic matter whose molecular weight was smaller than 1500 Da had significant effects on residual aluminum. All the treatment processes were ineffective in removing dissolved organic matter whose molecular weight was smaller than1500 Da. These results also indicated that the addition of sand or polyacrylamide in the coagulation process could greatly decrease the concentration of humic acid, and the concentration of residual aluminum also decreased. These results revealed that for all water samples after filtration, the majority of total residual aluminum existed in the form of total dissolved aluminum, accounting for 70%–90%. The concentration of residual aluminum produced in bovine serum albumin solutions indicated that when the DOC was larger than4.0 mg/L, there were still significant differences when the solution p H value varied from 4.0 to 9.0.

关键词： Coagulation Residual aluminum Organic matter Floc size Fractal dimension

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Representing Model Uncertainty by Multi-Stochastic Physics Approaches in the GRAPES Ensemble

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Advances in Atmospheric Sciences 2020年第4期37卷 328-346页

作者： zhizhen xu Jing CHEN Zheng JIN Hongqi LI Fajing CHEN Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081China Numerical Weather Prediction Center China Meteorological AdministrationBeijing 100081China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

To represent model uncertainties more comprehensively,a stochastically perturbed parameterization(SPP)scheme consisting of temporally and spatially varying perturbations of 18 parameters in the microphysics,convection,boundary layer,and surface layer parameterization schemes,as well as the stochastically perturbed parameterization tendencies(SPPT)scheme,and the stochastic kinetic energy backscatter(SKEB)scheme,is applied in the Global and Regional Assimilation and Prediction Enhanced System-Regional Ensemble Prediction System(GRAPES-REPS)to evaluate and compare the general performance of various combinations of multiple stochastic physics *** experiments are performed for a summer month(1-30 June 2015)over China and multiple verification metrics are *** results show that:(1)All stochastic experiments outperform the control(CTL)experiment,and all combinations of stochastic parameterization schemes perform better than the single SPP scheme,indicating that stochastic methods can effectively improve the forecast skill,and combinations of multiple stochastic parameterization schemes can better represent model uncertainties;(2)The combination of all three stochastic physics schemes(SPP,SPPT,and SKEB)outperforms any other combination of two schemes in precipitation forecasting and surface and upper-air verification to better represent the model uncertainties and improve the forecast skill;(3)Combining SKEB with SPP and/or SPPT results in a notable increase in the spread and reduction in outliers for the upper-air wind *** directly perturbs the wind field and therefore its addition will greatly impact the upper-air wind-speed fields,and it contributes most to the improvement in spread and outliers for wind;(4)The introduction of SPP has a positive added value,and does not lead to large changes in the evolution of the kinetic energy(KE)spectrum at any wavelength;(5)The introduction of SPPT and SKEB would cause a 5%-10%and 30%-80%change in the KE of mesosc

关键词： ensemble prediction model uncertainty stochastically perturbed parameterization multi-stochastic physics approaches

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Influence of coagulation mechanisms and floc formation on filterability

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Journal of Environmental Sciences 2017年第7期29卷 338-345页

作者： Ruyuan Jiao Rolando Fabris Christopher W.K.Chow Mary Drikas John van Leeuwen Dongsheng Wang zhizhen xu State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of Sciences Australian Water Quality Centre South Australian Water Corporation Centre for Water Management and Reuse School of Natural and Built EnvironmentsUniversity of South Australia Key Laboratory of Occupational Safety and Health Beijing Municipal Institute of Labor Protection

Minimizing particles in water is a key goal for improving drinking water quality and *** media filtration process,as the last step of the solid–liquid separation process,is largely influenced by the characteristics of flocs,which are formed and controlled within the coagulation *** a laboratory-based study,the impacts of the physical characteristics of flocs formed using aluminum sulfate on the filtration treatment of two comparative water samples were investigated using a photometric dispersion analyzer and a filterability *** general,the optimum dosage for maximizing filterability was higher than that for minimizing turbidity under neutral p H *** a monomeric aluminum-based coagulant,the charge neutralization mechanism produced better floc characteristics,including floc growth speed and size,than the sweep flocculation *** addition,the charge neutralization mechanism showed better performance compared to sweep flocculation in terms of DOC removal and floc filterability improvement for both waters,and showed superiority in turbidity removal only when the raw water had high *** the different mechanisms,the ways that floc characteristics impacted on floc filterability also *** low variation in floc size distribution obtained under the charge neutralization mechanism resulted in the flocs being amenable to removal by filtration *** the sweep flocculation mechanism,increasing the floc size improved the settling ability of flocs,resulting in higher filter efficiency.

关键词： Coagulation mechanisms Floc characteristics Filterability Turbidity

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消费文化视域下国产谍战剧的发展道路探析

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信阳农林学院学报 2022年第1期32卷 66-69,81页

作者：徐智臻信阳师范学院传媒学院河南信阳464000

近年来,国产谍战剧在消费文化的助力下,以新颖的叙事角度和多元化的人物形象构建,消解了观众对传统谍战剧的刻板印象,形成了独特的艺术风格,其商业价值与艺术价值日益被市场和受众认可。然而,当“谍战”被视为一种消费符号时,同质题材... 详细信息

近年来,国产谍战剧在消费文化的助力下,以新颖的叙事角度和多元化的人物形象构建,消解了观众对传统谍战剧的刻板印象,形成了独特的艺术风格,其商业价值与艺术价值日益被市场和受众认可。然而,当“谍战”被视为一种消费符号时,同质题材作品泛滥,剧情内容失当等泛娱乐化弊病频繁出现,伴随着受众趋同的审美心理、弱化的审美个性,消费文化开始消解电视文艺的审美创生,使得谍战剧偏离了其作为另类红色叙事方式的文化价值。本文从消费文化视域出发,分析当下国产谍战剧中的消费现象,就如何引导电视剧产业的健康发展,创作出既具历史意蕴、又彰显时代特色的主旋律谍战作品,提出看法和建议。

关键词：消费文化谍战剧审美创生

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Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

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Journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu xu Wenjing Liu Bing xu Zhifang xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by *** understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were *** rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global *** δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,*** end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate *** isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid *** on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely *** the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier ***,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

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