Identification des principales sources de PM10 impactant le nord de la France : Résultats préliminaires pour un site urbain à Nogent-sur-Oise

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The intense PM pollution episode in France during March 2015: multi-site approach and near real time data

The understanding of atmospheric particulate pollution represents one of the most important scientific challenges of our time, due various effects on climate and public health. These impacts are regularly highlighted during pollution episode occurring in densely urbanized areas. In Northern Europe, and more particularly in France, most intense and persistent episodes usually occur during spring, and are characterized by a large-scale pattern, covering most of the territory. Specific episodes are generally investigated from a single measurement point, describing the synergy between sources, chemical composition and meteorological conditions over a local to a regional scale. In this context, the development of aerosol mass spectrometry measurements greatly improved our knowledge of pollution (trans-)formation. Yet, this approach conceptually fails to get the bigger picture of large-scale pollution episodes, as multi-site characterization is needed. The presented work focuses on the investigation of the intense PM pollution episode that occurred in March 2015 from multi-site observations and near real time data. Aerosol Chemical Speciation Monitor (ACSM, Ng et al., 2011) and 7-wavelength aethalometer (AE33, Drinovec et al., 2015) measurements were carried out in Lyon, Metz, Creil and at SIRTA (Fig. 1)..

Etude des déterminants des concentrations en PM10 dans le nord de la France

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Characterising an intense PM pollution episode in March 2015 in France from multi-site approach and near real time data : Climatology, variabilities, geographical origins and model evaluation

International audienceDuring March 2015, a severe and large-scale particulate matter (PM) pollution episode occurred in France. Measurements in near real-time of the major chemical composition at four different urban background sites across the country (Paris, Creil, Metz and Lyon) allowed the investigation of spatiotemporal variabilities during this episode. A climatology approach showed that all sites experienced clear unusual rain shortage, a pattern that is also found on a longer timescale, highlighting the role of synoptic conditions over Wester-Europe. This episode is characterized by a strong predominance of secondary pollution, and more particularly of ammonium nitrate, which accounted for more than 50% of submicron aerosols at all sites during the most intense period of the episode. Pollution advection is illustrated by similar variabilities in Paris and Creil (distant of around 100 km), as well as trajectory analyses applied on nitrate and sulphate. Local sources, especially wood burning, are however found to contribute to local/ regional sub-episodes, notably in Metz. Finally, simulated concentrations from Chemistry-Transport model CHIMERE were compared to observed ones. Results highlighted different patterns depending on the chemical components and the measuring site, reinforcing the need of such exercises over other pollution episodes and sites

Comparison of PM10 Sources Profiles at 15 French Sites Using a Harmonized Constrained Positive Matrix Factorization Approach

International audienceReceptor-oriented models, including positive matrix factorization (PMF) analyses, are now commonly used to elaborate and/or evaluate action plans to improve air quality. In this context, the SOURCES project has been setup to gather and investigate in a harmonized way 15 datasets of chemical compounds from PM 10 collected for PMF studies during a five-year period (2012-2016) in France. The present paper aims at giving an overview of the results obtained within this project, notably illustrating the behavior of key primary sources as well as focusing on their statistical robustness and representativeness. Overall, wood burning for residential heating as well as road transport were confirmed to be the two main primary sources strongly influencing PM 10 loadings across the country. While wood burning profiles, as well as those dominated by secondary inorganic aerosols, present a rather good homogeneity among the sites investigated, some significant variabilities were observed for primary traffic factors, illustrating the need to better characterize the diversity of the various vehicle exhaust and non-exhaust emissions. Finally, natural sources, such as sea salts (widely observed in internal mixing with anthropogenic compounds), primary biogenic aerosols and/or terrigenous particles, were also found as non-negligible PM 10 components at every investigated site

Importance of the PBOA fraction of PM10

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Arabitol, mannitol, and glucose as tracers of primary biogenic organic aerosol: the influence of environmental factors on ambient air concentrations and spatial distribution over France

International audienceThe primary sugar compounds (SCs, defined as glucose, arabitol, and mannitol) are widely recognized as suitable molecular markers to characterize and apportion primary biogenic organic aerosol emission sources. This work improves our understanding of the spatial behavior and distribution of these chemical species and evidences their major effective environmental drivers. We conducted a large study focusing on the daily (24 h) PM 10 SC concentrations for 16 increasing space scale sites (local to nationwide), over at least 1 complete year. These sites are distributed in several French geographic areas of different environmental conditions. Our analyses, mainly based on the examination of the short-term evolutions of SC concentrations, clearly show distance-dependent correlations. SC concentration evo-lutions are highly synchronous at an urban city scale and remain well correlated throughout the same geographic re-Published by Copernicus Publications on behalf of the European Geosciences Union. 11014 A. Samaké et al.: Arabitol, mannitol, and glucose as tracers of primary biogenic organic aerosol gions, even if the sites are situated in different cities. However , sampling sites located in two distinct geographic areas are poorly correlated. Such a pattern indicates that the processes responsible for the evolution of the atmospheric SC concentrations present a spatial homogeneity over typical areas of at least tens of kilometers. Local phenomena, such as the resuspension of topsoil and associated microbiota, do no account for the major emissions processes of SC in urban areas not directly influenced by agricultural activities. The concentrations of SC and cellulose display remarkably synchronous temporal evolution cycles at an urban site in Greno-ble, indicating a common source ascribed to vegetation. Additionally , higher concentrations of SC at another site located in a crop field region occur during each harvest periods, indicating resuspension processes of plant materials (crop de-tritus, leaf debris) and associated microbiota for agricultural and nearby urbanized areas. Finally, ambient air temperature, relative humidity, and vegetation density constitute the main effective drivers of SC atmospheric concentrations