AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Source Apportionment of Submicron Aerosol Particles in a Mediterranean Harbour by Using a Rolling Window Approach
BENJAMIN CHAZEAU, Grégory Gille, Boualem Mesbah, Brice Temime-Roussel, Francesco Canonaco, Andre S.H. Prévôt, Barbara D'Anna, Henri Wortham, Nicolas Marchand, Aix-Marseille Université, CNRS, LCE FRE 3416
Abstract Number: 157 Working Group: Source Apportionment
Abstract Marseille is the largest harbour of the Mediterranean Sea and is a challenging environment for air quality. In order to document, on the long-term, the physico-chemical properties of fine particles, their sources and their evolution from day to multiyear period scales, we implemented an aerosol supersite in an urban background environment: Marseille-Longchamp (MRS-LCP).
A real-time dataset collected between February 2017 and August 2018 is presented here. ToF-ACSM organic aerosol (OA) mass spectra were analyzed by means of Positive Matrix Factorization (PMF) using the multilinear engine (ME-2) approach. This dataset was also used to test a new time-dependent source profiles evaluation to capture the variability of the sources over the year. It was achieved by performing PMF on a rolling window.
This analysis revealed very contrasted seasonal OA sources contributions and pointed out the overwhelming importance of local air masses circulation. Biomass Burning Organic Aerosol (BBOA) is the dominant aerosol source during winter, mainly advected from inland by nocturnal breezes. In such conditions, the total PM concentration can increase by up a factor of 5 in less than 15 min. During summer the OA mass concentration is dominated by secondary organic aerosol but the most interesting feature regards the submicron particles number concentration and their size distribution. Very intense plumes (Ntot>80 000 cm-3) associated with SO2 and metals are observed systematically when sea breezes bring back over the city air masses impacted by industrial and shipping emissions.