Using a Coupled Air Quality Modeling System for the Development of an Air Quality Plan in Madrid (Spain): Source Apportionment and Analysis Evaluation of Mitigation Measures

In this contribution, we use a coupled air quality modelling system (AQM) as a tool to design and develop an air quality plan in Madrid. AQM has allowed us to obtain a preliminary evaluation of the effect of mitigation measures over regional and local air quality levels. To achieve these goals, we have prepared a sophisticated AQM, coupling the meteorological model WRF, the emission model AEMM, and the photochemical model CMAQ. AQM was evaluated using the whole modelling year 2010 working with high horizontal resolution, 3 km for the region of Madrid and 1km for urban metropolitan area of Madrid. Two different analyses have been realized: a source apportionment exercise following a zero-out methodology to obtain the contribution to the air quality levels of the different emission sector;and an evaluation of the main mitigation measures considered in the air quality plan using sensitivity analysis. The air quality plan was focused on the improvement of NO2 levels and AQM analyzed the effect of the mitigation measures during ten episodes of 2011 where NO2 or O3 levels were the highest of the year;so we analyzed the effect of the mitigation plan in worst conditions. Results provided by the AQM system show that it accomplishes the European Directive modelling uncertainty requirements and the mean absolute gross error for 1-h maximum daily NO2 is 31% over locations with higher levels of this atmospheric pollutant;the road traffic is the main contributor to the air quality levels providing a 81% for NO2, 67% for CO and 46% for PM10;measures defined in the plan achieve to reduce up to 11 μgm-3 NO2 levels offering highest reductions over urban areas with traffic influence.

Preliminary Results of Application Mobilev Traffic model to Calculate Air Emission and Assessing Policies for Reducing Air Emissions in an ASEAN City

Traffic is one of the main air pollution source in urban cities,especially in Ho Chi Minh City.Annually,it emits a huge amount of pollutants into the atmosphere;and air quality in HCMC becomes worse due to circulation of outdate private vehicles.Therefore,clean air plan(CAP)is necessary for reducing air pollution level in the city and air emission inventory(EI)is an essential step to develop CAP.Mobilev model from Germany was chosen to conduct EI for HCMC.Objectives include of this study:(i)elaborating an air emission inventory(EI)from road traffic activities over HCMC;and(ii)assessing emission control policies and study abatement strategies to reduce air pollution level from traffic activities for HCMC in 2020.The results indicated that motorcycles are the main sources of air emission in HCMC.The emissions of CO are 3,586.707 tons/year,following ish VOC,NOx,CH4,NO2,SO2 and particulate matter(PM).In addition,CO2,which is one of the main greenhouse gases,also included and contributed 36,293.501 ton/year.These pollutants concentrated in the center which has crowded roads and population,affecting directly human health.Therefore,a replaced private vehicle with public transportation is necessary to reduce emissions.Two abatement strategies to 2020 for reducing emissions were performed and showed that if the HCMC government has severe policies on motor vehicles,the emission will be reduced until 60%,opposite emissions in 2020 will be increased to 200%.

A study on wildfire impacts on greenhouse gas emissions and regional air quality in South of Orléans,France

Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global climate.In September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS satellite.Based on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were characterized.Significant increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air quality.Emission factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous studies.Changes in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and discussed.Moreover,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission inventories.Current biomass burning emission inventories have uncertainties in estimating small fire burned areas and emissions.For instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant overestimation.Considering that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.

Comprehensive and high-resolution emission inventory of atmospheric pollutants for the northernmost cities agglomeration of Harbin-Changchun,China:Implications for local atmospheric environment management

Using a bottom-up estimation method,a comprehensive,high-resolution emission inventory of gaseous and particulate atmospheric pollutants for multiple anthropogenic sectors with typical local sources has been developed for the Harbin-Changchun city agglomeration(HCA).The annual emissions for CO,NO_(x),SO_(2),NH_(3),VOC S,PM_(2.5),PM 10,BC and OC during 2017 in the HCA were estimated to be 5.82 Tg,0.70 Tg,0.34 Tg,0.75 Tg,0.81 Tg,0.67 Tg,1.59 Tg,0.12 Tg and 0.26 Tg,respectively.For PM 10 and SO_(2),the emissions from industry processes were the dominant contributors representing 54.7%and 49.5%,respectively,of the total emissions,while 95.3%and 44.5%of the total NH_(3)and NO x emissions,respectively,were from or associated with agricultural activities and transportation.Spatiotemporal distributions showed that most emissions(except NH_(3))occurred in November to March and were concentrated in the central cities of Changchun and Harbin and the surrounding cities.Open burning of straw made an important contribution to PM_(2.5)in the central regions of the northeastern plain during autumn and spring,while domestic coal combustion for heating purposes was significant with respect to SO_(2)and PM_(2.5)emissions during autumn and winter.Furthermore,based on Principal Component Analysis and Multivariable Linear Regression model,air temperature,relative humidity,electricity and energy consumption,and the urban and rural population were optimized to be representative indicators for rapidly assessing the magnitude of regional atmospheric pollutants in the HCA.Such indicators and equations were demonstrated to be useful for local atmospheric environment management.

Implementation of the Air Quality Monitoring Network at Agadir City in Morocco

Air pollution is a major global issue with widely known harmful effects on human health and the environment. This pollution is a very complex phenomenon given the diversity of pollutants that may be present in the atmosphere. The air quality in urban areas is of a great concern for residents living in cities and represents a current issue that requires an adequate management. So that air quality policy is driven by health concerns. In this paper, we present an overview on the experience of Agadir city to establish the air quality management policy, local authority on the whole have developed a good understanding of air quality in the area. Indeed for several years, efforts have been made to monitor the air quality in this city, this translated by air quality assessment since 2006 using mobile laboratory and fixed station. Our goals in this study were to review the operation of Local Air Quality Management (LAQM) making better use of available resources to improve its outcomes and make recommendations with a view to improving air quality issues. This work highlights the requirement to revise periodically the LAQM for generating priority for air quality issues within local authority and the need to implement the optimizing Air Quality Monitoring Network (AQMN).

Evaluation of Anthropogenic Air Emissions from Marine Engines in a Coastal Urban Airshed of Texas

Corpus Christi, Texas, is a growing urban area with a busy port and a petrochemical industrial base that is currently in compliance with the US Environmental Protection Agency’s (EPA) National Ambient Air Quality Standards (NAAQS) for ozone. However, the Texas Commission on Environmental Quality (TCEQ) has classified this urban airshed as a near non-attainment area. A comprehensive annual air emission inventory based on marine engines activity was developed for the years of 2006-2009 for the Port of Corpus Christi, Texas using recent EPA approved methodology. A regional-scale photochemical model Comprehensive Air Modeling system with extensions (CAMx) was used to evaluate the impact of these emissions on the ground level ozone concentrations by zeroing out the emissions and employing Direct Decoupled Method (DDM) for sensitivity analysis to estimate the 8-hour ozone sensitivity coefficients due to NOx and VOC emissions from marine engines. The analysis has shown a localized increase of up to 7.8 ppb in the 8-hour ozone concentration very close to the port premises and a decrease of about 1.73 ppb further downwind. Ozone sensitivity analysis using DDM on the 8-hour ozone concentrations showed a higher sensitivity to NOx emissions. Thus, any NOx related controls of marine engines will benefit local urban and regional ozone levels.

Model-Measurement Comparison of Ammonia Bi-Directional Air-Surface Exchange Fluxes over Agricultural Fields

Modeled and measured bi-directional fluxes (BDFs) of ammonia (NH3) were compared over fertilized soybean and corn canopies for three intensive sampling periods: the first, during the summer of 2002 in Warsaw, North Carolina (NC), USA;and the second and third during the summer of 2007 in Lillington, NC. For the first and the third experimental periods, the BDF model produced reasonable diurnal flux patterns. The model also produced correct flux directions (emission and dry deposition) and magnitudes under dry and wet canopy conditions and during day and nighttime for these two periods. However, the model fails to produce the observed very high upward fluxes from the second sampling period due to the fertilization application (and thus being much higher soil emission potentials in the field than the default model values), although this can be improved by adjusting model input of soil emission potentials. Model-measurement comparison results suggest that the model is likely capable for improving long-term or regional scale ammonia predictions if implemented in chemical transport models replace the traditional dry deposition models, although modifications are needed when applying to specific situations.

VOC emission caps constrained by air quality targets based on response surface model:A case study in the Pearl River Delta Region,China

Because of the recent growth in ground-level ozone and increased emission of volatile organic compounds(VOCs),VOC emission control has become a major concern in China.In response,emission caps to control VOC have been stipulated in recent policies,but few of them were constrained by the co-control target of PM_(2.5)and ozone,and discussed the factor that influence the emission cap formulation.Herein,we proposed a framework for quantification of VOC emission caps constrained by targets for PM_(2.5)and ozone via a new response surface modeling(RSM)technique,achieving 50%computational cost savings of the quantification.In the Pearl River Delta(PRD)region,the VOC emission caps constrained by air quality targets varied greatly with the NOxemission reduction level.If control measures in the surrounding areas of the PRD region were not considered,there could be two feasible strategies for VOC emission caps to meet air quality targets(160μg/m^(3)for the maximum 8-hr-average 90th-percentile(MDA8-90%)ozone and 25μg/m^(3)for the annual average of PM_(2.5)):a moderate VOC emission cap with<20%NOxemission reductions or a notable VOC emission cap with>60%NOxemission reductions.If the ozone concentration target were reduced to 155μg/m^(3),deep NOxemission reductions is the only feasible ozone control measure in PRD.Optimization of seasonal VOC emission caps based on the Monte Carlo simulation could allow us to gain higher ozone benefits or greater VOC emission reductions.If VOC emissions were further reduced in autumn,MDA8-90%ozone could be lowered by 0.3-1.5μg/m^(3),equaling the ozone benefits of 10%VOC emission reduction measures.The method for VOC emission cap quantification and optimization proposed in this study could provide scientific guidance for coordinated control of regional PM_(2.5)and O_(3)pollution in China.

黄河流域水环境问题研究现状、挑战与展望

黄河流域生态保护和高质量发展是国家重大发展战略,保护黄河是事关中华民族伟大复兴和永续发展的千秋大计.近年来,黄河流域水环境质量明显改善,但有限的水资源和脆弱的生态系统使得黄河流域水环境保护仍面临巨大的挑战.科学诊断黄河流域重大水环境问题是新时期治理黄河的前提和关键.本文围绕黄河流域水环境问题诊断这一主题,聚焦黄河流域断面水质改善的核心需求,首先分析黄河流域水环境现状,发现黄河流域整体水质持续向好,但干支流水质改善不同步,流域主要污染指标时空差异显著,中下游和部分支流污染严重;其次梳理国内外相关研究进展和主要挑战,总结断面水质提升所需的核心理论与技术,如水环境承载力评价、污染排放清单构建与水环境模型模拟等方面的应用与发展趋势,发现黄河流域存在气候变化影响下水沙变化大、现有排放清单分辨率不足、水环境模拟缺乏多尺度污染排放-断面水质响应关系研究等问题,难以支撑未来精细化水环境管理.对黄河流域水环境研究的未来发展进行了展望,建议未来在以下几个方面开展进一步研究,包括气候变化下黄河流域水环境承载力研究、黄河流域高分辨率排放清单构建、多尺度污染排放与断面水质响应关系.

Accurate prediction of air quality response to emissions for effective control policy design

Designing effective control policy requires accurate quantification of the relationship between the ambient concentrations of O3and PM2.5and the emissions of their precursors.However,the challenge is that precursor reduction does not necessarily lead to decreases in the concentrations of O3and PM2.5,which are formed by multiple precursors under complex physical and chemical processes;this calls for the development of advanced model technologies to provide accurate predictions of the nonlinear responses of air quality to emissions.Different from the traditional sensitivity analysis and source apportionment methods,the reduced form models(RFMs)based on chemical transport models(CTMs)are able to quantify air quality responses to emissions more accurately and efficiently with lower computational cost.Here we review recent approaches used in RFMs and compare their structures,advantages and disadvantages,performance and applications.In general,RFMs are classified into three types including(1)sensitivity-based models,(2)models with simplified chemistry and physical processes,and(3)statistical models,with considerable differences in principles,characteristics and application ranges.The prediction of nonlinear responses by RFMs enables more in-depth analysis,not only in terms of real-time prediction of concentrations and quantification of human exposure,health impacts and economic damage,but also in optimizing control policies.Notably,data assimilation and emission inventory inversion based on the nonlinear response of concentrations to emissions can also be greatly beneficial to air pollution control management.In future studies,improvement in the performance of CTMs is exceedingly crucial to obtain a more reliable baseline for the prediction of air quality responses.Development of models to determine the air quality response to emissions under varying meteorological conditions is also necessary in the context of future climate changes,which pose great challenges to the quantification of response relationships.Additionally,with rising requirements for fine-scale air quality management,improving the performance of urban-scale simulations is worth considering.In short,accurate predictions of the response of air quality to emissions,though challenging,holds great promise for the present as well as for future scenarios.

An emission source inversion model based on satellite data and its application in air quality forecasts

This paper aims at constructing an emission source inversion model using a variational processing method and adaptive nudging scheme for the Community Multiscale Air Quality Model (CMAQ) based on satellite data to investigate the applicability of high resolution OMI (Ozone Monitoring Instrument) column concentration data for air quality forecasts over the North China. The results show a reasonable consistency and good correlation between the spatial distributions of NO2 from surface and OMI satellite measurements in both winter and summer. Such OMI products may be used to implement integrated variational analysis based on observation data on the ground. With linear and variational corrections made, the spatial distribution of OMI NO2 clearly revealed more localized distributing characteristics of NO2 concentration. With such information, emission sources in the southwest and southeast of North China are found to have greater impacts on air quality in Beijing. When the retrieved emission source inventory based on high-resolution OMI NO2 data was used, the coupled Weather Research Forecasting CMAQ model (WRF-CMAQ) performed significantly better in forecasting NO2 concentration level and its tendency as reflected by the more consistencies between the NO2 concentrations from surface observation and model result. In conclusion, satellite data are particularly important for simulating NO2 concentrations on urban and street-block scale. High-resolution OMI NO2 data are applicable for inversing NOx emission source inventory, assessing the regional pollution status and pollution control strategy, and improving the model forecasting results on urban scale.

Numerical study on the ozone formation inside street canyons using a chemistry box model

Tropospheric ozone is a secondary air pollutant produced in the presence of nitrogen oxides (NO_x),volatile organic compounds (VOCs),and solar radiation.In an urban environment,ground-level vehicular exhaust is the major anthropogenic source of ozone precursors.In the cases of street canyons,pollutant dilution is weakened by the surrounding buildings that creates localized high concentration of NO_x and VOCs,and thus leads to high potential of ozone formation.By considering the major physical and chemical p...

Evaluation of the Impact of the Handling and Storage System of Petroleum Coke on PM10 Emissions in an Oil Refinery

The objective of this study was to identify the impact of the coke handling and storage system on the emission of PM10 particulate material.The methodology was based on AP-42 emission factors from U.S.EPA(United States Environmental Protection Agency)for the calculation of PM10 emissions from operations in the handling and storage of petroleum coke in an oil refinery in the northeastern of Brazil.The knowledge of the emission potential of each operation of the coke handling and storage system allows the adoption of more effective control measures,contributing to the effective reduction of PM10 emissions in this system.To complement the environmental impact assessment of each configuration,an air quality modelling was performed using the atmospheric dispersion software.The comparison performed in this study enables authors to conclude,even for a totally mechanic system,that adopts control measures,PM10 emissions are low when confronted with the remaining sources of an oil refinery.By analyzing emissions from automated systems operation(scenario 1),it can be observed that the source with higher emission potential is the stockpile,which represents 60%of the system’s emission.Transfer and transport operations by conveyor belts together correspond to 40%of emissions.Even though transfer operations also represent a significant part(27%),they are not clustered in a unique point,making these emissions abatement difficult.The same is valid for transport using conveyor belts.Emissions from the piles are really the most significant.For this reason,this work concentrated efforts in the storage area,the ones that motivate the majority of studies relating to abatement technologies.

EmissV: A Preprocessor for WRF-Chem Model

Air quality models are tools capable to predict the physical and chemical processes that affect air pollutants as they disperse and reacts in the atmosphere. These models need input containing meteorological data, terrestrial data and emissions. Meteorological and terrestrial data comes from different sources such as meteorological stations and satellite images which are important to represent the current state of the atmosphere and are available at least on a daily frequency. On the other hand, the emission data comes from pollution inventories generated mainly from governmental reports, this data needs to be processed by various reasons such as the correction of outdated emissions, for combining inventories or to speciate the emitted pollutants to different chemical mechanisms. EmissV is a code written into a high-level programming language to create emissions input for these atmospheric models. The emissions from EmissV are coherent with the total and the spatial distribution of emissions obtained from other preprocessors.

Characterization of aircraft emissions and air quality impacts of an international airport

Beijing Capital International Airport（ZBAA） is the world＇s second busiest airport. In this study, the emissions of air pollutants from aircraft and other sources at ZBAA in 2015 were estimated using an improved method, which considered the mixing layer height calculated based on aircraft meteorological data relay（AMDAR）, instead of using the height（915 m）recommended by ICAO. The yearly emissions of NOx, CO, VOCs, SO2, and PM2.5 at the airport were 8.76 × 10^3, 4.43 × 10^3, 5.43 × 10^2, 4.80 × 10^2, and 1.49 × 10^2 ton/year, respectively. The spatial–temporal distribution of aircraft emissions was systematically analyzed to understand the emission characteristics of aircraft. The results indicated that NOxwas mainly emitted during the take-off and climb phases, accounting for 20.5% and 55.5% of the total emissions. CO and HC were mainly emitted during the taxi phase, accounting for 91.6%and 92.2% of the total emissions. Because the mixing layer height was high in summer, the emissions of aircraft were at the highest level throughout the year. Based on the detailed emissions inventory, four seasons simulation using WRF-CMAQ model was performed over the domain surrounding the airport. The results indicated that the contribution to PM2.5 was relatively high in winter; the average impact was about 1.15 μg/m3 within a radius of1 km around the airport. Meanwhile, the near surroundings and southwest areas of the airport are the most sensitive to PM2.5.

上海市PM_(2.5)和臭氧复合污染期多路径减排效果评估

为探究大气PM_(2.5)和臭氧(O_(3))复合污染期间的污染物浓度削峰方案,以上海市2018年4月27—30日PM_(2.5)和O_(3)复合污染时段为研究对象,结合区域多尺度空气质量模型(CMAQ模型),建立上海市O_(3)日最大8小时滑动平均值(MDA8 O_(3))以及PM_(2.5)浓度与人为源排放的NO_(x)和VOCs之间的响应关系,获得了EKMA(empirical kinetics modeling approach,经验动力学建模方法)曲线.在此基础上,探讨上海市MDA8 O_(3)和PM_(2.5)对前体物排放的敏感性,并进一步量化了本地减排、提前减排和区域减排等不同情景下PM_(2.5)和MDA8 O_(3)的浓度变化.结果表明:(1)上海市PM_(2.5)和O_(3)复合污染期间MDA8 O_(3)的峰值率(PR)为0.6~1.1,除浦东惠南站点外,整体处于VOCs控制区.(2)上海市人为源NO_(x)和VOCs减排对PM_(2.5)的削峰效果有限(NO_(x)减少80%时,PM_(2.5)浓度下降1.2μg/m^(3)).本地VOCs减排对MDA8 O_(3)的削峰较为明显(最大下降量为17.0μg/m^(3)).VOCs与NO_(x)的减排比例需控制在1.9∶1以上才能使MDA8 O_(3)浓度不发生反弹,同时可优先控制烯烃类的排放.(3)上海市MDA8 O_(3)浓度在提前减排和区域减排VOCs情景下均能进一步降低,降幅为0.6%~3.1%,且区域减排带来的受益范围更广;提前减排和区域减排对上海市PM_(2.5)浓度降低的边际效益均甚微.研究显示,复合污染期间VOCs的排放控制可同时削减PM_(2.5)和MDA8 O_(3)浓度峰值,提前采取污染防控措施以及区域联合控制对上海市O_(3)浓度削峰有一定积极意义.

Developing China's roadmap for air quality improvement:A review on technology development and future prospects

Air pollution control policies in China have been experiencing profound changes,highlighting a strategic transformation from total pollutant emission control to air quality improvement,along with the shifting targets starting from acid rain and NO_(x)emissions to PM_(2.5)pollution,and then the emerging O_(3)challenges.The marvelous achievements have been made with the dramatic decrease of SO_(2)emission and fundamental improvement of PM_(2.5)concentration.Despite these achievements,China has proposed Beautiful China target through 2035 and the goal of 2030 carbon peak and 2060 carbon neutrality,which impose stricter requirements on air quality and synergistic mitigation with Greenhouse Gas(GHG)emissions.Against this background,an integrated multi-objective and multi-benefit roadmap is required to provide decision support for China’s long-term air quality improvement strategy.This paper systematically reviews the technical system for developing the air quality improvement roadmap,which was integrated from the research output of China’s National Key R&D Program for Research on Atmospheric Pollution Factors and Control Technologies(hereafter Special NKP),covering mid-and long-term air quality target setting techniques,quantitative analysis techniques for emission reduction targets corresponding to air quality targets,and pathway optimization techniques for realizing reduction targets.The experience and lessons derived from the reviews have implications for the reformation of China’s air quality improvement roadmap in facing challenges of synergistic mitigation of PM_(2.5)and O_(3),and the coupling with climate change mitigation.

城市大气污染物来源特征

以北京市为案例,介绍一种包括污染物排放清单建立、环境空气质量模拟及区域环境影响分析等方法在内的城市大气污染物来源特征分析的整体技术方法,从而确定城市大气污染物的排放分布及浓度分布特征、行业排放分担率及浓度贡献、地区排放分担率及浓度贡献以及区域污染对城市环境空气质量影响等多方面特征,为城市大气污染的控制决策提供必要的理论支持。对北京市的研究结果表明:对PM10,扬尘和工业为主要当地污染源;对SO2,采暖和工业为主要当地污染源;对NOx,交通和工业为主要当地污染源;对3种主要大气污染物,石景山、朝阳南等工业区以及老城区对北京市的大气环境造成重要影响,为需要优先控制的地区;北京市周边污染源对北京环境气质量有较大影响,其中RM10的影响最大(高达47 3%),北京市应同时加强对局地污染与区域污染的控制。

北京市水泥工业大气污染物排放清单及污染特征

采用排放因子法估算2010年北京市水泥工业颗粒物TSP和气态污染物SO2、NOx、氟化物的排放总量，从而建立了水泥工业大气污染物排放清单，并分析其主要大气污染物排放时空分布特征及对全市总排放量的贡献情况。结果表明：（1）水泥工业NOx污染较为严重，NOx排放占全市总排放量的6．72％；（2）水泥工业作为点源污染，在局部范围内对周围空气及居民有较大的影响；（3）利用ADMS—URBAN模型进行大气污染贡献分析，水泥工业TSP排放对环境空气质量贡献0．100-0．169μg／m3（1h），SOs排放对环境空气质量贡献0.0285-0．0652μg／m3（1h），NOx排放对环境空气质量贡献0．324-0．760μg／ma（1h），NOx对空气质量影响较大。