1. On-going developments of SinG: particles
K. Sartelet, L. Lugon, Y. Kim et al.
CEREA, Joint laboratory ENPC-EDF R&D, Université Paris-Est, Marne-la-Vallée, France

2. Introduction
Particles or particulate matter (PM): tiny pieces of solid or liquid matter in suspension in the atmosphere.
Emissions (primary): traffic, industries, ocean, desert, wildfire
Secondary: formed by chemical reactions in the atmosphere

3. Introduction: impact of particles
Particles impact:
human health,
climate,
visibility
March Low-pollution day 3

4. Introduction: chemical composition of particles in Paris
PM2.5 AUTEUIL = 26 µg m-3
PM2.5 PARIS = 15 µg m-3
Close to road traffic
Urban background
Source : Source apportionment of airborne particles in the Île-de-France region, AIRPARIF, 2011.
In streets with traffic, high concentrations of
organic matter (OM)
Elementary carbon (EC)
Other compounds from large-scale transport

5. Primary vs secondary organic aerosols (SOA)
Organic Matter
Primary vs secondary organic aerosols (SOA)
Secondary particles
Primary organic particles
Black carbon
Secondary particules
Source : Platt et al., Atmos. Chem. Phys, 13, , 2013

6. Aerosol modelling

7. Aerosol dynamic
Discretisation of particle size (diameter)
Discretisation of particle size and composition
Ultrafine particles are better modelled with a sectional than a modal approach
SCRAM: aerosol dynamic for particles of different sizes and compositions

8. Organics in the emissions
Volatile
Gas
VOC
(Volatile organic compounds)
Regulated
Condensable products
IVOC
Not regulated
SVOC
Particles
PM - OM
Non-volatile

9. Ageing of organic emissions
VOC
SVOC
Oxidation
Increase of the organic mass OM

10. VOC and I/S-VOC precursors of OM
Amongst VOC, not all chemical species are SOA precursors.
For anthropogenic emissions, the main known precursors are aromatics and high molecular weight molecules (I/S-VOC).
Biogenic emissions (trees) also emits VOC (isoprene, terpenes) precursors of OM
=> Need to represent trees in streets and to understand the influence on air quality of trees in streets

11. Conclusion
In streets with traffic, higher concentrations of organic matter (OM) and elementary carbon (EC).
OM precursors are emitted in the gas phase, as VOC and I/S-VOC.
Aerosol model (SCRAM) currently being coupled to SinG to model primary and secondary compounds of aerosols in streets.
PhD thesis of Lya Lugon with application to Paris
Role of trees in streets