2017, Bozzetti, Carlo, El Haddad, Imad, Salameh, Dalia, Daellenbach, Kaspar Rudolf, Fermo, Paola, Gonzalez, Raquel, Minguillón, María Cruz, Iinuma, Yoshiteru, Poulain, Laurent, Elser, Miriam, Müller, Emanuel, Slowik, Jay Gates, Jaffrezo, Jean-Luc, Baltensperger, Urs, Marchand, Nicolas, Prévôt, André Stephan Henry

We investigated the seasonal trends of OA sources affecting the air quality of Marseille (France), which is the largest harbor of the Mediterranean Sea. This was achieved by measurements of nebulized filter extracts using an aerosol mass spectrometer (offline-AMS). In total 216 PM2.5 (particulate matter with an aerodynamic diameter < 2.5 μm) filter samples were collected over 1 year from August 2011 to July 2012. These filters were used to create 54 composite samples which were analyzed by offline-AMS. The same samples were also analyzed for major water-soluble ions, metals, elemental and organic carbon (EC/OC), and organic markers, including n-alkanes, hopanes, polycyclic aromatic hydrocarbons (PAHs), lignin and cellulose pyrolysis products, and nitrocatechols. The application of positive matrix factorization (PMF) to the water-soluble AMS spectra enabled the extraction of five factors, related to hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), oxygenated OA (OOA), and an industry-related OA (INDOA). Seasonal trends and relative contributions of OA sources were compared with the source apportionment of OA spectra collected from the AMS field deployment at the same station but in different years and for shorter monitoring periods (February 2011 and July 2008). Online- and offline-AMS source apportionment revealed comparable seasonal contribution of the different OA sources. Results revealed that BBOA was the dominant source during winter, representing on average 48 % of the OA, while during summer the main OA component was OOA (63 % of OA mass on average). HOA related to traffic emissions contributed on a yearly average 17 % to the OA mass, while COA was a minor source contributing 4 %. The contribution of INDOA was enhanced during winter (17 % during winter and 11 % during summer), consistent with an increased contribution from light alkanes, light PAHs (fluoranthene, pyrene, phenanthrene), and selenium, which is commonly considered as a unique coal combustion and coke production marker. Online- and offline-AMS source apportionments revealed evolving levoglucosan : BBOA ratios, which were higher during late autumn and March. A similar seasonality was observed in the ratios of cellulose combustion markers to lignin combustion markers, highlighting the contribution from cellulose-rich biomass combustion, possibly related to agricultural activities.

2023, Trechera, Pedro, Garcia-Marlès, Meritxell, Liu, Xiansheng, Reche, Cristina, Pérez, Noemí, Savadkoohi, Marjan, Beddows, David, Salma, Imre, Vörösmarty, Máté, Casans, Andrea, Casquero-Vera, Juan Andrés, Hueglin, Christoph, Marchand, Nicolas, Chazeau, Benjamin, Gille, Grégory, Kalkavouras, Panayiotis, Mihalopoulos, Nikos, Ondracek, Jakub, Zikova, Nadia, Niemi, Jarkko V., Manninen, Hanna E., Green, David C., Tremper, Anja H., Norman, Michael, Vratolis, Stergios, Eleftheriadis, Konstantinos, Gómez-Moreno, Francisco J., Alonso-Blanco, Elisabeth, Gerwig, Holger, Wiedensohler, Alfred, Weinhold, Kay, Merkel, Maik, Bastian, Susanne, Petit, Jean-Eudes, Favez, Olivier, Crumeyrolle, Suzanne, Ferlay, Nicolas, Martins Dos Santos, Sebastiao, Putaud, Jean-Philippe, Timonen, Hilkka, Lampilahti, Janne, Asbach, Christof, Wolf, Carmen, Kaminski, Heinz, Altug, Hicran, Hoffmann, Barbara, Rich, David Q., Pandolfi, Marco, Harrison, Roy M., Hopke, Philip K., Petäjä, Tuukka, Alastuey, Andrés, Querol, Xavier

The 2017–2019 hourly particle number size distributions (PNSD) from 26 sites in Europe and 1 in the US were evaluated focusing on 16 urban background (UB) and 6 traffic (TR) sites in the framework of Research Infrastructures services reinforcing air quality monitoring capacities in European URBAN & industrial areaS (RI-URBANS) project. The main objective was to describe the phenomenology of urban ultrafine particles (UFP) in Europe with a significant air quality focus. The varying lower size detection limits made it difficult to compare PN concentrations (PNC), particularly PN10-25, from different cities. PNCs follow a TR > UB > Suburban (SUB) order. PNC and Black Carbon (BC) progressively increase from Northern Europe to Southern Europe and from Western to Eastern Europe. At the UB sites, typical traffic rush hour PNC peaks are evident, many also showing midday-morning PNC peaks anti-correlated with BC. These peaks result from increased PN10-25, suggesting significant PNC contributions from nucleation, fumigation and shipping. Site types to be identified by daily and seasonal PNC and BC patterns are: (i) PNC mainly driven by traffic emissions, with marked correlations with BC on different time scales; (ii) marked midday/morning PNC peaks and a seasonal anti-correlation with PNC/BC; (iii) both traffic peaks and midday peaks without marked seasonal patterns. Groups (ii) and (iii) included cities with high insolation. PNC, especially PN25-800, was positively correlated with BC, NO2, CO and PM for several sites. The variable correlation of PNSD with different urban pollutants demonstrates that these do not reflect the variability of UFP in urban environments. Specific monitoring of PNSD is needed if nanoparticles and their associated health impacts are to be assessed. Implementation of the CEN-ACTRIS recommendations for PNSD measurements would provide comparable measurements, and measurements of <10 nm PNC are needed for full evaluation of the health effects of this size fraction.