Wintertime aerosol chemical composition and source apportionment of the organic fraction in the metropolitan area of Paris

Abstract

The effect of a post-industrial megacity on local and regional air quality was assessed via a month-long field measurement campaign in the Paris metropolitan area during winter 2010. Here we present source apportionment results from three aerosol mass spectrometers and two aethalometers deployed at three measurement stations within the Paris region. Submicron aerosol composition is dominated by the organic fraction (30–36%) and nitrate (28–29%), with lower contributions from sulfate (14–16%), ammonium (12–14%) and black carbon (7–13%). <br><br> Organic source apportionment was performed using positive matrix factorization, resulting in a set of organic factors corresponding both to primary emission sources and secondary production. The dominant primary sources are traffic (11–15% of organic mass), biomass burning (13–15%) and cooking (up to 35% during meal hours). Secondary organic aerosol contributes more than 50% to the total organic mass and includes a highly oxidized factor from indeterminate and/or diverse sources and a less oxidized factor related to wood burning emissions. Black carbon was apportioned to traffic and wood burning sources using a model based on wavelength-dependent light absorption of these two combustion sources. The time series of organic and black carbon factors from related sources were strongly correlated. The similarities in aerosol composition, total mass and temporal variation between the three sites suggest that particulate pollution in Paris is dominated by regional factors, and that the emissions from Paris itself have a relatively low impact on its surroundings

Organic aerosol composition and sources in Pasadena, California, during the 2010 CalNex campaign

“…The HOA and CIOA spectra are compared in detail in section D of the supporting information. The diurnal cycle of CIOA exhibits peaks near mealtimes with a smaller peak between 14:00 and 15:00 PDT and a larger peak between 21:00 and 22:00 PDT similar to the cooking organic aerosol diurnal cycles observed for other field measurements [Allan et al, 2010;Crippa et al, 2013;Mohr et al, 2011;Sun et al, 2011]. The lunchtime and dinnertime peaks are both slightly delayed from traditional American mealtimes.…”

Contributions of local and regional sources to fine PM in the megacity of Paris

“…Significant levels of secondary species were transported to Paris when the corresponding air masses originated from continental Europe. The importance of the regional sources in Paris was also confirmed by Crippa et al (2013) for the winter MEGAPOLI period.…”

Direct observation of aqueous secondary organic aerosol from biomass-burning emissions

“…In Europe, combustion of biomass for residential heating has increased in recent years. One study at a rural site in northern Italy showed that SOA from biomass burning in winter accounts for 10% of organic carbon and 7% of fine particle mass (43); in the urban area of Paris, processing of biomassburning emissions accounted for up to 40% of the OA during another field study (44); similarly, in rural areas nearby London, aged biomass-burning emissions are a likely important contribution to the overall OA (45). This study highlights the relevance of aqueousphase chemistry for processing of wood-burning emissions.…”