European aerosol phenomenology - 8 : Harmonised source apportionment of organic aerosol using 22 Year-long ACSM/AMS datasets

Organic aerosol (OA) is a key component of total submicron particulate matter (PM1), and comprehensive knowledge of OA sources across Europe is crucial to mitigate PM1 levels. Europe has a well-established air quality research infrastructure from which yearlong datasets using 21 aerosol chemical speciation monitors (ACSMs) and 1 aerosol mass spectrometer (AMS) were gathered during 2013-2019. It includes 9 non-urban and 13 urban sites. This study developed a state-of-the-art source apportionment protocol to analyse long-term OA mass spectrum data by applying the most advanced source apportionment strategies (i.e., rolling PMF, ME-2, and bootstrap). This harmonised protocol was followed strictly for all 22 datasets, making the source apportionment results more comparable. In addition, it enables quantification of the most common OA components such as hydrocarbon-like OA (HOA), biomass burning OA (BBOA), cooking-like OA (COA), more oxidised-oxygenated OA (MO-OOA), and less oxidised-oxygenated OA (LO-OOA). Other components such as coal combustion OA (CCOA), solid fuel OA (SFOA: mainly mixture of coal and peat combustion), cigarette smoke OA (CSOA), sea salt (mostly inorganic but part of the OA mass spectrum), coffee OA, and ship industry OA could also be separated at a few specific sites. Oxygenated OA (OOA) components make up most of the submicron OA mass (average = 71.1%, range from 43.7 to 100%). Solid fuel combustion-related OA components (i.e., BBOA, CCOA, and SFOA) are still considerable with in total 16.0% yearly contribution to the OA, yet mainly during winter months (21.4%). Overall, this comprehensive protocol works effectively across all sites governed by different sources and generates robust and consistent source apportionment results. Our work presents a comprehensive overview of OA sources in Europe with a unique combination of high time resolution (30-240 min) and long-term data coverage (9-36 months), providing essential information to improve/validate air quality, health impact, and climate models.Peer reviewe

Identification/Investigation of some Q-ACSM issues to ensure QA/QC of data for proper export for PMF analysis

International audienc

Multi-year datasets of PM1 chemical composition and organic aerosol sources in different French urban and suburban areas

International audienc

Source apportionment analysis on one-year ACSM data of organic aerosols from Lille, Northern France, using Rolling PMF

International audienceThe study of aerosol particle sources is essential to improve air quality, thus reducing their health impacts (Kelly et Fussell 2015). In Europe, more than 400 000 premature deaths have been attributed to fine particle exposure (EEA 2020). France, for instance, is still affected by relatively high particle matter (PM) concentrations and, with several exceedances the daily PM2.5 concentration of 25 μg m-3 recommended by WHO (EEA 2020). More specifically, the north of France is considered a pollution hotspot, affected by heavy traffic, high urban density, significant agricultural activities overlapped with transnational pollution transport (UK, Benelux, Germany, etc.)

5-year analysis of submicron aerosol chemical composition and organic aerosol source apportionment at a suburban site in North-Western Europe

International audienceIn Europe, more than 307 000 premature deaths havebeen attributed to fine particle exposure (EEA, 2021). Inparticular, northern France is affected by relatively highparticle matter (PM) concentrations, frequentlyexceeding the new annual PM2.5 concentration of 5μg m-3 recommended by the WHO (EEA, 2021).Therefore, the study of aerosol particle sources isessential to improve air quality and to better developeffective mitigation policies.In this context, an Aerosol Chemical SpeciationMonitor (ACSM) and an aethalometer (AE33) have beenrunning quasi continuously since 2016 at a suburbansite in Lille, known as the ATOLL (AtmosphericObservations in liLLe) platform, located on theUniversity of Lille campus. The objective is to provide acomprehensive dataset of the chemical composition ofsubmicron aerosol particles (PM1), and to investigateOrganic Aerosol (OA) sources in the region throughsource apportionment analysis using Positive MatrixFactorization (PMF). Wind and back-trajectory analysisare also used to help identifying the geographical originsof advected aerosol particles, especially since Lille is atthe crossroads of transnational pollution transport fromBelgium, Germany, the Netherlands and the UK.Here, we present the first long-term analysis ofnon-refractory PM1 (NR-PM1) from October 2016 untilDecember 2020. The average NR-PM1 concentrationwas 9.7 μg m-3, which was dominated by OA (45.4 %)followed by nitrate (31.4 %), ammonium (13.4 %) andsulfate (9.4 %). To study OA origins, we used the rollingPMF algorithm, analyzing one-month windows shiftedby one-week step. Such approach combined with welldefinedconstraints has the advantage of capturing thepotential temporal changes in the source profilesthroughout the seasons and years.The OA PMF analysis yielded two primary OAfactors: a traffic related hydrocarbon-like OA (HOA) andbiomass burning OA (BBOA), and two oxygenated OA(OOA) factors. HOA showed a fairly constantcontribution to OA throughout the seasons (with anaverage contribution of 12 %), while BBOA varied from8 % to 18.5 %, with a peak in winter due to increasedemissions from residential wood combustion. The OOAfactors were distinguished between their less and moreoxidized fractions (LO-OOA and MO-OOA, respectively).They contributed substantially to the total OA mass,with an average of 74 % (32 % and 42 % for LO-OOA andMO-OOA, respectively), indicating a strong participationof aged/secondary processes to local aerosol levels. Aregional signature of those OOA factors is confirmed viawind and trajectory analysis, identifying the impact ofpolluted continental air masses from central Europe.During winter, the correlation between BBOA and LOOOAsuggests the influence of aged biomass burning onthe latter, identifying at least half of OA to be associatedto wood combustion during wintertime. This wasconfirmed by complementary PMF analyses includinginorganic and black carbon components.Overall, this study provides a thorough analysis ofsubmicron aerosol sources at the recently establishedATOLL platform, depicting complex interactionsbetween regional traffic, wood burning, and agriculturalactivities in the highly urbanized North-WesternEuropean region.This work was supported by the French Ministry ofEnvironment, through the CARA program. It is also partof the Labex CaPPA project (ANR-11-LABX-0005-01), andthe CLIMIBIO project, both also funded by the RegionalCouncil “Hauts-de-France” and the European RegionalDevelopment Fund (ERDF)

Multi-annual source apportionment and absorbing properties of organic aerosols in northern France

International audienceTo quantify accurately the adverse effects of the particulate matter (PM) fine fraction on climate, it is necessary to identify emission sources and associate them with aerosol radiative properties over long periods. Source apportionment is a useful tool to quantify PM contributions especially for organic aerosols (OA). Four years of real-time optical and chemical observations were combined to characterize OA sources and their absorbing properties at the ATOLL platform in Northern France. Positive Matrix Factorization (PMF) shows high contribution (74%) of oxygenated OA (OOA), followed by 14% of BBOA (due to biomass burning) and 12% of HOA (related to traffic) on average for the mass concentrations. Meanwhile, OA are responsible for 27% of light absorption at 370 nm, showing a significant contribution of Brown Carbon (BrC). A Multiple Linear Regression (MLR) analysis applied to determine source-specific Mass Absorption Efficiencies (MAE) of the OA factors highlights BBOA as the dominant source of BrC light absorption (64%)

Multi-annual source apportionment and absorbing properties of organic aerosols in northern France

To quantify accurately the adverse effects of the particulate matter (PM) fine fraction on climate, it is necessary to identify emission sources and associate them with aerosol radiative properties over long periods. Source apportionment is a useful tool to quantify PM contributions especially for organic aerosols (OA). Four years of real-time optical and chemical observations were combined to characterize OA sources and their absorbing properties at the ATOLL platform in Northern France. Positive Matrix Factorization (PMF) shows high contribution (74%) of oxygenated OA (OOA), followed by 14% of BBOA (due to biomass burning) and 12% of HOA (related to traffic) on average for the mass concentrations. Meanwhile, OA are responsible for 27% of light absorption at 370 nm, showing a significant contribution of Brown Carbon (BrC). A Multiple Linear Regression (MLR) analysis applied to determine source-specific Mass Absorption Efficiencies (MAE) of the OA factors highlights BBOA as the dominant source of BrC light absorption (64%)

European aerosol phenomenology − 8: Harmonised source apportionment of organic aerosol using 22 Year-long ACSM/AMS datasets

Organic aerosol (OA) is a key component of total submicron particulate matter (PM1), and comprehensive knowledge of OA sources across Europe is crucial to mitigate PM1 levels. Europe has a well-established air quality research infrastructure from which yearlong datasets using 21 aerosol chemical speciation monitors (ACSMs) and 1 aerosol mass spectrometer (AMS) were gathered during 2013–2019. It includes 9 non-urban and 13 urban sites. This study developed a state-of-the-art source apportionment protocol to analyse long-term OA mass spectrum data by applying the most advanced source apportionment strategies (i.e., rolling PMF, ME-2, and bootstrap). This harmonised protocol was followed strictly for all 22 datasets, making the source apportionment results more comparable. In addition, it enables quantification of the most common OA components such as hydrocarbon-like OA (HOA), biomass burning OA (BBOA), cooking-like OA (COA), more oxidised-oxygenated OA (MO-OOA), and less oxidised-oxygenated OA (LO-OOA). Other components such as coal combustion OA (CCOA), solid fuel OA (SFOA: mainly mixture of coal and peat combustion), cigarette smoke OA (CSOA), sea salt (mostly inorganic but part of the OA mass spectrum), coffee OA, and ship industry OA could also be separated at a few specific sites. Oxygenated OA (OOA) components make up most of the submicron OA mass (average = 71.1%, range from 43.7 to 100%). Solid fuel combustion-related OA components (i.e., BBOA, CCOA, and SFOA) are still considerable with in total 16.0% yearly contribution to the OA, yet mainly during winter months (21.4%). Overall, this comprehensive protocol works effectively across all sites governed by different sources and generates robust and consistent source apportionment results. Our work presents a comprehensive overview of OA sources in Europe with a unique combination of high time resolution (30–240 min) and long-term data coverage (9–36 months), providing essential information to improve/validate air quality, health impact, and climate models.ISSN:0160-4120ISSN:1873-675

<i>Rolling</i> vs. <i>seasonal</i> PMF: real-world multi-site and synthetic dataset comparison

International audienceAbstract. Particulate matter (PM) has become a major concern in terms of human health and climate impact. In particular, the source apportionment (SA) of organic aerosols (OA) present in submicron particles (PM1) has gained relevance as an atmospheric research field due to the diversity and complexity of its primary sources and secondary formation processes. Moreover, relatively simple but robust instruments such as the Aerosol Chemical Speciation Monitor (ACSM) are now widely available for the near-real-time online determination of the composition of the non-refractory PM1. One of the most used tools for SA purposes is the source-receptor positive matrix factorisation (PMF) model. Even though the recently developed rolling PMF technique has already been used for OA SA on ACSM datasets, no study has assessed its added value compared to the more common seasonal PMF method using a practical approach yet. In this paper, both techniques were applied to a synthetic dataset and to nine European ACSM datasets in order to spot the main output discrepancies between methods. The main advantage of the synthetic dataset approach was that the methods' outputs could be compared to the expected “true” values, i.e. the original synthetic dataset values. This approach revealed similar apportionment results amongst methods, although the rolling PMF profile's adaptability feature proved to be advantageous, as it generated output profiles that moved nearer to the truth points. Nevertheless, these results highlighted the impact of the profile anchor on the solution, as the use of a different anchor with respect to the truth led to significantly different results in both methods. In the multi-site study, while differences were generally not significant when considering year-long periods, their importance grew towards shorter time spans, as in intra-month or intra-day cycles. As far as correlation with external measurements is concerned, rolling PMF performed better than seasonal PMF globally for the ambient datasets investigated here, especially in periods between seasons. The results of this multi-site comparison coincide with the synthetic dataset in terms of rolling–seasonal similarity and rolling PMF reporting moderate improvements. Altogether, the results of this study provide solid evidence of the robustness of both methods and of the overall efficiency of the recently proposed rolling PMF approach. </jats:p

European aerosol phenomenology − 8: Harmonised source apportionment of organic aerosol using 22 Year-long ACSM/AMS datasets

Organic aerosol (OA) is a key component of total submicron particulate matter (PM1), and comprehensive knowledge of OA sources across Europe is crucial to mitigate PM1 levels. Europe has a well-established air quality research infrastructure from which yearlong datasets using 21 aerosol chemical speciation monitors (ACSMs) and 1 aerosol mass spectrometer (AMS) were gathered during 2013–2019. It includes 9 non-urban and 13 urban sites. This study developed a state-of-the-art source apportionment protocol to analyse long-term OA mass spectrum data by applying the most advanced source apportionment strategies (i.e., rolling PMF, ME-2, and bootstrap). This harmonised protocol was followed strictly for all 22 datasets, making the source apportionment results more comparable. In addition, it enables quantification of the most common OA components such as hydrocarbon-like OA (HOA), biomass burning OA (BBOA), cooking-like OA (COA), more oxidised-oxygenated OA (MO-OOA), and less oxidised-oxygenated OA (LO-OOA). Other components such as coal combustion OA (CCOA), solid fuel OA (SFOA: mainly mixture of coal and peat combustion), cigarette smoke OA (CSOA), sea salt (mostly inorganic but part of the OA mass spectrum), coffee OA, and ship industry OA could also be separated at a few specific sites. Oxygenated OA (OOA) components make up most of the submicron OA mass (average = 71.1%, range from 43.7 to 100%). Solid fuel combustion-related OA components (i.e., BBOA, CCOA, and SFOA) are still considerable with in total 16.0% yearly contribution to the OA, yet mainly during winter months (21.4%). Overall, this comprehensive protocol works effectively across all sites governed by different sources and generates robust and consistent source apportionment results. Our work presents a comprehensive overview of OA sources in Europe with a unique combination of high time resolution (30–240 min) and long-term data coverage (9–36 months), providing essential information to improve/validate air quality, health impact, and climate models