Eurodelta multi-model simulated and observed particulate matter trends in Europe in the period of 1990-2010

The Eurodelta-Trends (EDT) multi-model experiment, aimed at assessing the efficiency of emission mitigation measures in improving air quality in Europe during 1990-2010, was designed to answer a series of questions regarding European pollution trends; i.e. were there significant trends detected by observations? Do the models manage to reproduce observed trends? How close is the agreement between the models and how large are the deviations from observations? In this paper, we address these issues with respect to particulate matter (PM) pollution. An in-depth trend analysis has been performed for PM10 and PM2.5 for the period of 2000-2010, based on results from six chemical transport models and observational data from the EMEP (Cooperative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe) monitoring network. Given harmonization of set-up and main input data, the differences in model results should mainly result from differences in the process formulations within the models themselves, and the spread in the model-simulated trends could be regarded as an indicator for modelling uncertainty.The model ensemble simulations indicate overall decreasing trends in PM10 and PM2.5 from 2000 to 2010, with the total reductions of annual mean concentrations by between 2 and 5 (7 for PM10) mu g m(-3) (or between 10 % and 30 %) across most of Europe (by 0.5-2 mu g m(-3) in Fennoscandia, the north-west of Russia and eastern Europe) during the studied period. Compared to PM2.5, relative PM10 trends are weaker due to large interannual variability of natural coarse PM within the former. The changes in the concentrations of PM individual components are in general consistent with emission reductions. There is reasonable agreement in PM trends estimated by the individual models, with the inter-model variability below 30 %-40 % over most of Europe, increasing to 50 %-60 % in the northern and eastern parts of the EDT domain.Averaged over measurement sites (26 for PM10 and 13 for PM2.5), the mean ensemble-simulated trends are - 0.24 and -0.22 mu g m(-3) yr(-1) for PM10 and PM2.5, which are somewhat weaker than the observed trends of - 0.35 and -0.40 mu g m(-3) yr(-1) respectively, partly due to model underestimation of PM concentrations. The correspondence is better in relative PM10 and PM2.5 trends, which are -1.7 % yr(-1) and -2.0 % yr(-1) from the model ensemble and -2.1 % yr(-1) and -2.9 % yr(-1) from the observations respectively. The observations identify significant trends (at the 95 % confidence level) for PM10 at 56 % of the sites and for PM2.5 at 36 % of the sites, which is somewhat less that the fractions of significant modelled trends. Further, we find somewhat smaller spatial variability of modelled PM trends with respect to the observed ones across Europe and also within individual countries.The strongest decreasing PM trends and the largest number of sites with significant trends are found for the summer season, according to both the model ensemble and observations. The winter PM trends are very weak and mostly insignificant. Important reasons for that are the very modest reductions and even increases in the emissions of primary PM from residential heating in winter. It should be kept in mind that all findings regarding modelled versus observed PM trends are limited to the regions where the sites are located.The analysis reveals considerable variability of the role of the individual aerosols in PM10 trends across European countries. The multi-model simulations, supported by available observations, point to decreases in SO42- concentrations playing an overall dominant role. Also, we see relatively large contributions of the trends of NH4+ and NO3- to PM10 decreasing trends in Germany, Denmark, Poland and the Po Valley, while the reductions of primary PM emissions appear to be a dominant factor in bringing down PM10 in France, Norway, Portugal, Greece and parts of the UK and Russia. Further discussions are given with respect to emission uncertainties (including the implications of not accounting for forest fires and natural mineral dust by some of the models) and the effect of inter-annual meteorological variability on the trend analysis.Peer reviewe

Air pollution trends in the EMEP region between 1990 and 2012

The present report synthesises the main features of the evolution over the 1990-2012 time period of the concentration and deposition of air pollutants relevant in the context of the Convention on Long-range Transboundary Air Pollution: (i) ozone, (ii) sulfur and nitrogen compounds and particulate matter, (iii) heavy metals and persistent organic pollutants. It is based on observations gathered in State Parties to the Convention within the EMEP monitoring network of regional background stations, as well as relevant modelling initiatives. Joint Report of: EMEP Task Force on Measurements and Modelling (TFMM), Chemical Co-ordinating Centre (CCC), Meteorological Synthesizing Centre-East (MSC-E), Meteorological Synthesizing Centre-West (MSC-W)

Particulate matters modelling : Participation to Eurodelta and application at a reffinery

Les modèles Eulériens de chimie-transport simulent les phénomènes de formation des polluants atmosphériques dans des mailles de résolution horizontale qui sont généralement de l’ordre de plusieurs kilomètres. Les panaches issus des sources industrielles, de dimensions initiales de l’ordre du mètre, sont donc artificiellement dilués, détériorant alors la représentation de leur impact potentiel sur la qualité de l'air ambiant. Une approche de modèle de panache sous-maille peut-être mise en œuvre pour traiter ce problème. Le modèle de panache sous-maille de Polyphemus traite les émissions des sources ponctuelles industrielles par l'intermédiaire d'un modèle à bouffées gaussiennes qui interagit dynamiquement avec un modèle eulérien. Ceci permet de modéliser la qualité de l’air à grande échelle (régionale à continentale), tout en gardant une bonne représentation des panaches, y compris à l’échelle locale.Les travaux menés dans le cadre de cette thèse ont permis d’améliorer le modèle de panache sous-maille de Polyphemus en intégrant une représentation plus fine de la granulométrie des particules, et d’approfondir les évaluations du modèle à différentes échelles. Ils ont été réalisés selon deux phases principales.La première consiste en l’évaluation à l'échelle continentale du modèle eulérien de Polyphemus dans le cadre de l'exercice d'intercomparaison Eurodelta. La phase actuelle du programme vise à étudier les tendances de pollution à l’échelle de l’Europe sur les vingt dernières années, ainsi que la sensibilité de ces tendances modélisées aux données météorologiques, aux émissions européennes et aux émissions extra-européennes (implicitement représentées par les conditions aux limites). Dans ce contexte, les performances du modèle eulérien de Polyphemus sont évaluées en comparaison à sept autres modèles. Pour cette thèse, l'étude se concentre plus spécifiquement sur l’évaluation de la modélisation des concentrations en aérosols organiques secondaires (AOS), et leurs sensibilités aux différentes paramétrisations utilisées par les modèles participants.La seconde phase présente l’utilisation du modèle de panache sous maille de Polyphemus dans le contexte de différentes campagnes de mesures. En premier lieu, le modèle est appliqué dans le contexte d’une campagne de mesures réalisée en avril 2013 au voisinage de la raffinerie Total de Grandpuits en Seine-et-Marne. Cette étude a permis d'évaluer les performances du modèle à l’échelle de la région Île-de-France et à l'échelle locale. La contribution de la raffinerie aux concentrations en particules inhalables, en interaction avec les autres sources locales, a été analysée. En second lieu, le modèle est appliqué dans le contexte des deux campagnes d'observation du projet TEMMAS (« TEledetection, Measure, Modeling of Atmospherics pollutants on industrial Site »), réalisées au voisinage de la raffinerie Total de La Mède dans les Bouches-du-Rhône en septembre 2015 et février 2016. Les performances du modèle sont évaluées en comparaison à des mesures intensives de concentrations en masse et en nombre et de composition des particules au voisinage de la raffinerie de la MèdeEulerian Chemical-Transport Models (CTM) simulate the formation of atmospheric pollutants in gridded domain with horizontal resolutions that are usually of the order of several kilometers. Industrial plumes emitted from elevated stacks with initial dimensions of a few meters are, therefore, artificially diluted in those grid cells, thereby deteriorating the representation of their potential impact on local air quality. A Plume-in-Grid modeling approach may be used to improve the representation of industrial plumes. The Polyphemus Plume-in-Grid model treats point source emissions with a Gaussian puff model, dynamically interacting with an Eulerian model. This approach allows one to model air quality at several scales (regional to continental) while ensuring a good representation of industrial plumes from local to continental scales.In this thesis, the Polyphemus Plume-in-Grid model has been improved by integrating a finer representation of the particle size distribution. Several studies were also conducted in order to further the model performance evaluation at various scales. This thesis consists of two main parts.The first part covers the evaluation of the Polyphemus Eulerian model at the continental scale, in the context of the Eurodelta model intercomparison project. The current phase of Eurodelta consists in studying pollution trends at the European scale over the past two decades and the sensitivity of those trends to meteorology, European emissions, and extra-European emissions (represented in the models by the boundary conditions). In this context, the performance statistics of the Polyphemus Eulerian model are evaluated in comparison to seven other CTM. This thesis focuses principally on secondary organic aerosol (SOA) modeling, and their sensitivity to various parameterizations used in the participating CTM.The second part presents applications of the Polyphemus Plume-in-Grid modelto different field measurement campaigns. The first campaign focuses on the month of April 2013, in the vicinity of the Total refinery of Grandpuits, Seine-et-Marne. Model performance is evaluated at the regional scale, with the refinery sources treated with the Plume-in-Grid representation. The refinery contribution to local respirable particle concentrations, in interaction with local sources, is analyzed. Next, the model is applied to two measurement campaigns of the TEMMAS project (“TEledetection, Measure, Modeling of Atmospheric pollutants on industrial sites”), conducted in the vicinity of the Total refinery at La Mède, Bouches-du-Rhône, in September 2015 and February 2016. The performance of the Polyphemus Plume-in-Grid model is evaluated with intensive measurements of mass concentrations, number concentrations, and chemical composition of particles in the vicinity of the refiner

Modélisation des particules : Participation à Eurodelta et étude au voisinage d'une raffinerie

Eulerian Chemical-Transport Models (CTM) simulate the formation of atmospheric pollutants in gridded domain with horizontal resolutions that are usually of the order of several kilometers. Industrial plumes emitted from elevated stacks with initial dimensions of a few meters are, therefore, artificially diluted in those grid cells, thereby deteriorating the representation of their potential impact on local air quality. A Plume-in-Grid modeling approach may be used to improve the representation of industrial plumes. The Polyphemus Plume-in-Grid model treats point source emissions with a Gaussian puff model, dynamically interacting with an Eulerian model. This approach allows one to model air quality at several scales (regional to continental) while ensuring a good representation of industrial plumes from local to continental scales.In this thesis, the Polyphemus Plume-in-Grid model has been improved by integrating a finer representation of the particle size distribution. Several studies were also conducted in order to further the model performance evaluation at various scales. This thesis consists of two main parts.The first part covers the evaluation of the Polyphemus Eulerian model at the continental scale, in the context of the Eurodelta model intercomparison project. The current phase of Eurodelta consists in studying pollution trends at the European scale over the past two decades and the sensitivity of those trends to meteorology, European emissions, and extra-European emissions (represented in the models by the boundary conditions). In this context, the performance statistics of the Polyphemus Eulerian model are evaluated in comparison to seven other CTM. This thesis focuses principally on secondary organic aerosol (SOA) modeling, and their sensitivity to various parameterizations used in the participating CTM.The second part presents applications of the Polyphemus Plume-in-Grid modelto different field measurement campaigns. The first campaign focuses on the month of April 2013, in the vicinity of the Total refinery of Grandpuits, Seine-et-Marne. Model performance is evaluated at the regional scale, with the refinery sources treated with the Plume-in-Grid representation. The refinery contribution to local respirable particle concentrations, in interaction with local sources, is analyzed. Next, the model is applied to two measurement campaigns of the TEMMAS project (“TEledetection, Measure, Modeling of Atmospheric pollutants on industrial sites”), conducted in the vicinity of the Total refinery at La Mède, Bouches-du-Rhône, in September 2015 and February 2016. The performance of the Polyphemus Plume-in-Grid model is evaluated with intensive measurements of mass concentrations, number concentrations, and chemical composition of particles in the vicinity of the refineryLes modèles Eulériens de chimie-transport simulent les phénomènes de formation des polluants atmosphériques dans des mailles de résolution horizontale qui sont généralement de l’ordre de plusieurs kilomètres. Les panaches issus des sources industrielles, de dimensions initiales de l’ordre du mètre, sont donc artificiellement dilués, détériorant alors la représentation de leur impact potentiel sur la qualité de l'air ambiant. Une approche de modèle de panache sous-maille peut-être mise en œuvre pour traiter ce problème. Le modèle de panache sous-maille de Polyphemus traite les émissions des sources ponctuelles industrielles par l'intermédiaire d'un modèle à bouffées gaussiennes qui interagit dynamiquement avec un modèle eulérien. Ceci permet de modéliser la qualité de l’air à grande échelle (régionale à continentale), tout en gardant une bonne représentation des panaches, y compris à l’échelle locale.Les travaux menés dans le cadre de cette thèse ont permis d’améliorer le modèle de panache sous-maille de Polyphemus en intégrant une représentation plus fine de la granulométrie des particules, et d’approfondir les évaluations du modèle à différentes échelles. Ils ont été réalisés selon deux phases principales.La première consiste en l’évaluation à l'échelle continentale du modèle eulérien de Polyphemus dans le cadre de l'exercice d'intercomparaison Eurodelta. La phase actuelle du programme vise à étudier les tendances de pollution à l’échelle de l’Europe sur les vingt dernières années, ainsi que la sensibilité de ces tendances modélisées aux données météorologiques, aux émissions européennes et aux émissions extra-européennes (implicitement représentées par les conditions aux limites). Dans ce contexte, les performances du modèle eulérien de Polyphemus sont évaluées en comparaison à sept autres modèles. Pour cette thèse, l'étude se concentre plus spécifiquement sur l’évaluation de la modélisation des concentrations en aérosols organiques secondaires (AOS), et leurs sensibilités aux différentes paramétrisations utilisées par les modèles participants.La seconde phase présente l’utilisation du modèle de panache sous maille de Polyphemus dans le contexte de différentes campagnes de mesures. En premier lieu, le modèle est appliqué dans le contexte d’une campagne de mesures réalisée en avril 2013 au voisinage de la raffinerie Total de Grandpuits en Seine-et-Marne. Cette étude a permis d'évaluer les performances du modèle à l’échelle de la région Île-de-France et à l'échelle locale. La contribution de la raffinerie aux concentrations en particules inhalables, en interaction avec les autres sources locales, a été analysée. En second lieu, le modèle est appliqué dans le contexte des deux campagnes d'observation du projet TEMMAS (« TEledetection, Measure, Modeling of Atmospherics pollutants on industrial Site »), réalisées au voisinage de la raffinerie Total de La Mède dans les Bouches-du-Rhône en septembre 2015 et février 2016. Les performances du modèle sont évaluées en comparaison à des mesures intensives de concentrations en masse et en nombre et de composition des particules au voisinage de la raffinerie de la Mèd

Plume-in-grid model for the evaluation of particulate matter contribution of industrial point and volume sources: application to refinery sources in the Paris region

International audienc

Use of Polyphemus Plume in Grid model to reproduce the full chemistry and physics of Particulate matter in industrial plumes. Applications and validation for Refinery during the TEMMAS project "Teledetection, Measure, Modeling of Atmospheric pollutants on industrial Sites"

International audienceThe Polyphemus Plume-in-Grid (PinG) model, based on a 3D Eulerian model and a subgrid scaled Gaussian puff model was developed to represent the dispersion and transformation of air pollutants in industrial plumes. The PinG model computes the formation of secondary gases and PM in the plumes, resulting from the oxidation of emitted precursors in interaction with background pollutant concentrations. The model was improved to treat PM number concentrations, allowing a better representation of the ultra-fine fraction of PM concentrations. In comparison with the conventional CTM approach, this tool is able to provide a realistic assessment of the impacts of industrial sites in the first ten kilometers. To improve the validation of the Plume In Grid Model, from the stack to the ground, a research project called TEMMAS (TEledetection, Measure, Modeling of Atmospheric pollutants on industrial Sites) was supported by the French environment agency (ADEME). The project included two intensive measurement campaigns, which were conducted around a refinery in the south of France. The aim of these campaigns were to study the refinery PM microphysical signatures and its evolution with distance to the source in the first kilometers. During the campaigns different observation protocols of PM were deployed: • sample collection inside the principal stacks and around the refinery. • online measurements of microphysical properties of PM and trace gas concentrations; • optical measurement: airborne hyperspectral imagery in the reflective domain, According to the different techniques, two types of models were used, with different spatial resolutions, meteorological input (meso-scale meteorology or local measurements), and chemical transformations representations: • The Polyphemus Plume-in-Grid (PinG) model, which results are compared to measured PM in the vicinity of the refinery in terms of gas, PM mass and number concentrations, as a function of particle sizes and PM chemical compositions. • The Safety LAgrangian Model (SLAM), a lagrangian non reactive dispersion model using pre calculated CFD winds fields. The fine resolution (meter) allows to reproduce complex flows in industrial installations. This approach is better fitted for the comparison of the local scale plume dispersion with optical imaging

Caractérisation de panache d'aérosols par analyse multi-temporelle de données hyperspectrales

International audienceIn this paper we focus on airborne hyperspectral imaging methodology to characterize PM (Particulate Matter) near industrial emission sources. Two short-term intensive campaigns were carried out in the vicinity of a refinery in the South of France, in September 2015 and February 2016. Different protocols of in-situ PM measurements were performed, at stack measurements (flow rate and offline chemical analysis) and on-line measurement at the refinery border (size distribution, concentration and chemistry of aerosols). A multi temporal methodology to retrieve aerosol type, to map the aerosol concentration and to quantify mass flow rate from airborne hyperspectral data is described in this paper. This method applied to the refinery detected plume from the main stack yields a black carbon to sulfate ratio of 10/90 in mass inside the plume, with an average size distribution smaller than 100 nm. These results are in a good agreement with on-line analysis of aerosols at refinery border. The resulting quantitative map with a metric spatial resolution leads to a flow rate estimated of about 1g/s and is in a good agreement with in-situ stack measurements and modelling.Ce papier propose une méthodologie de caractérisation des PM (Particulate Matter) proches des sources industrielles par imagerie hyperspectrale aéroportée. Il s’appuie sur deux campagnes de mesures réalisées autour d’une raffinerie dans le sud de la France en Septembre 2015 et Février 2016. Différents protocoles de mesures in-situ des PM ont été réalisées dans ce cadre, mesures au niveau de l’émissaire principal (debit et analyse chimique) et mesures on-line au voisinage de la raffinerie (distribution en taille, concentration et analyse chimique). Une méthodologie multi-temporelle dédiée à l’inversion des types d’aérosols présents dans le panache permettant de fournir une carte en concentration d’aérosols et d’estimer le débit est décrite dans ce papier. Appliquée à ce cas d’étude, les resultats hyperspectraux ont permis d’estimer un rapport suie/sulfate de 10/90 en masse dans le panache avec une distribution en taille inférieure à 100nm. Ces résultats sont en bon accord avec les mesures in-situ. Les cartes en concentration obtenue à une resolution métrique permettent d’estimer un debit de l’ordre de 1g/s en bon accord avec les mesures in-situ au niveau de l’émissaire et avec les résultats de modélisation de dispersion des aerosols

Multi-model assessment of PM trends in europe during two decades (1990-2010)

The model trend analysis for PM10 and PM2.5, performed within the Eurodelta-Trends experiment, covers 21 year, from 1990 through 2010, with particular focus on the period 2001-2010 for which appropriate amount of PM observations is available. Eight chemical transport models (CTM) participated in the multi-modal trend analysis: EMEP/MSC-W, CHIMERE, LOTOS-EUROS, MINNI, MATCH, WRF-Chem, CMAQ and Polyphemus (out of which six models performed trend runs for the 21-year period). The average modelled trends are somewhat smaller than the observed, though the models identify significant PM trends at more sites in the period 2001-2010. There are considerable difference in the PM trends between the regions/countries and in different seasons. Investigation of the changes in PM chemical composition during the investigated period shows that the models differ in terms of relative contribution of the individual PM components to the PM trends. For the 2001-2010 period, the effcct of inter-annual meteorological variability appears more important relative to emission changes. Finally, we look at PM trends/changes during the 1990-2010 period

Overview of EURODELTA-TRENDS, the air quality Hindcast modelling exercise

A multi-model exercise has been set up by the Task Force on Measurement and Modelling of the Convention on Long-Range Transboundary of Air Pollution in order to assess the evolution of air quality in Europe since the early 1990s. The main science and policy question addressed by the exercise is to assess the efficiency of emission mitigation measures in improving the air quality at the continental scale. It is also expected that EURODELTA-TRENDS will better quantify (i) the capability of models (and underlying emission inventories) in simulating the long term evolution of air quality, (ii) the importance of intercontinental transport of air pollution through the boundary conditions of the regional models, (iii) the role of interannual meteorological variability. In order to cover a range of uncertainty, in addition to the model being used in support to the Convention (EMEP/MSC-W), six chemistry transport models participated to the exercise: Chimere, CMAQ, LOTOS-EUROS, MINNI, Polyphemus and WRF-CHEM. The modelling experiment is organised in three tiers: (i) a reference for the years 1990, 2000 and 2010, including also sensitivity simulations devoted to emission changes, (ii) six sensitivity simulations for boundary condition changes, (iii) full modelling of the complete 21-yr time series for 1990 to 2010. An overview of the experiment will be given as well as key results in terms of (i) trend modelling benchmarking and (ii) attribution of the main factors underlying the evolution over the past 20 years of particulate matter, ozone, and also acidifying and eutrophying pollution in Europe

Impacts of different representations of SOA on simulated trends : multi-model analysis in the framework of the Eurodelta-Trends exercise

Particulate organic matter represents an important fraction of PM2.5 mass in Europe (20 to 60%). The Chemistry Transport Models (CTM) tend to under-estimate secondary organic aerosol (SOA) concentrations and the causes are still poorly understood, due to the complexity of the formation process and the large number of species involved, originating from anthropogenic and biogenic sources. The formation of SOA is one of the topics addressed in the context of the Eurodelta-Trends exercise. For this exercise a common set of input data (meteorology, emissions, and boundary conditions) covering Europe for a twenty years period (1990-2010) has been developed. Seven regional models are used within this exercise (Chimere, CMAQ, MINNI, LOTOS-EUROS, EMEP-MSCW, Polyphemus, and WRF-Chem) to perform simulations at 25km resolution. In this work the SOA simulated by each participating model are compared for the three reference years (1990, 2000, and 2010). For the three years the models show similar features: similar anthropogenic SOA (ASOA) spatial distributions, but with large variability between models in terms of concentration levels. The same tendency is observed for the anthropogenic VOC, from which ASOA are formed. Concerning the biogenic fraction of SOA (BSOA), the results show a large variability in the spatial distributions while the distributions of the biogenic VOC emissions are similar. These differences can be attributed to the various oxidation processes included in the models, leading to different patterns of SOA precursors, formed from the oxidation of the emitted VOC. Furthermore, the gas phase chemical mechanisms and organic aerosol models are different for each regional model, leading to differences in the SOA precursor concentrations and in the gas/particles partitioning. Finally, the SOA analysis is extended to the whole Eurodelta-Trends period (1990-2010), in order to study the impact of these differences on the simulated trends over Europe during the last twenty years