1. Source apportionment of the carbonaceous aerosol – Quantitative estimates based on 14 C- and organic tracer analysis 1.Norwegian Institute for Air Research 2.Norwegian Meteorological Institute 3.Technical University of Vienna 4.Lund University Bordeaux 23 - 25 April 2008 KE Yttri 1, D Simpson 2, H. Puxbaum 3, K Stenström 4, T Svendby 1

2. SORGA - Main objectives Quantify the contribution of biogenic and anthropogenic carbonaceous matter to PM in the Nordic urban and rural environment Biogenic/anthropogenic fraction in urban and rural areas Separate the biogenic and the anthropogenic fraction into primary and secondary carbonaceous matter Size-distribution (PM 1 and PM 10 ) of biogenic and anthropogenic carboanceous matter Improve current knowledge of what are the concentrations of VOCs crucial for SOA-formation Improve the aerosol modules of the following models: MAPS -EPISODE - EMEP

3. SORGA - Measurements sites Oslo (Urban background) Hurdal (Rural Background) Oslo Hurdal Measurement campaigns Summer period: 19 June - 5 July 2006 Winter period: 1 - 8 Mars 2007

4. SORGA - Aerosol parameters measured Table 1: Input parameters for source apportionment of the particulate carbonaceous fraction Yttri et al. in progress ParameterSize fractionTime resolutionObjective Mass concentrationPM 1, PM 10 12 hoursPM concentration EC, OC p, TC p (QBQ)PM 1, PM 10 12 hoursCarbonaceous PM loading LevoglucosanPM 10 12 hoursWood burning Sugars and Sugar-alcoholsPM 1, PM 10 12 hoursFungal spores (PBAP) Cellulose 1 PM 1, PM 10 Grab samplePlant debris (PBAP) f M ( 14 C-analysis) 2 PM 1, PM 10 Grab sample day Grab sample night Separates between modern Carbon and fossil Carbon 1.Cellulose analysis performed at the Technical University of Vienna 2. 14 C-analysis performed at the University of Lund

5. SORGA - Sources of carbonaceous matter OC bsoa OC from biogenic sec. org. aerosols OC asoa OC from anthropogenic sec. org. aerosols OC bb OC from residential wood burning EC bb EC from residential wood burning OC ff OC from combustion of fossil fuel EC ff EC from combustion of fossil fuel OC pbs OC from fungal spores OC pbc OC from plant debris

6. SORGA - Equations and uncertainty estimates Confounding factors OCbsoa: OCnf  OCbsoa, OCmeat cooking, condensation of SVOC from biomass(?), PBAP not accounted for by sugars and sugar-alcohols Equations to calculate carbonaceous subfractions Table 2: Low, central and high factors used to estimate the carbonaceous subfractions using LHS

7. SORGA - Source apportionment of TC p in PM 10 Summer Hurdal (RB) PM 10 TC p = 2.9 ± 1.2 µg C m -3 Oslo (UB) PM 10 TC p = 3.7 ± 1.3 µg C m -3 Natural: 72% Anthropogenic: 28% Natural: 46% Anthropogenic: 54%

8. SORGA - Source apportionment of TC p in PM 1, Summer Hurdal (RB) PM 1 TC p = 1.7 ± 1.1 µg C m -3 Oslo (UB) PM 1 TC p = 2.3 ± 0.8 µg C m -3 Natural: 66% Anthropogenic: 34% Natural: 36% Anthropogenic: 64%

9. SORGA - Source apportionment of TC p in PM 10 Winter Hurdal (RB) PM 10 TC p = 1.2 ± 0.5 µg C m -3 Oslo (UB) PM 10 TC p = 3.2 ± 1.5 µg C m -3 Natural: 8% Anthropogenic: 92% Natural: 5% Anthropogenic: 95%

10. SORGA - Source apportionment of TC p in PM 10 Summer Day/night variation Oslo(UB) PM 10 DAY TC p = 3.8 ± 1.2 µg C m -3 Oslo (UB) PM 10 NIGHT TC p = 3.6 ± 1.4 µg C m -3 Natural: 52% Anthropogenic:48% Natural: 40% Anthropogenic:60% -3

11. SORGA - Relative cont. of carb. matter to PM 10 (Summer) Hurdal (RB) PM 10 PM 10 = 10.4 µg m -3 Oslo (UB) PM 10 PM 10 = 15.6 µg m -3 Conversion factors: OC bsoa = 1.8; OC pb = 1.6; OC bb = 2.0; EC bb and EC ff = 1.1; OC ff = 1.3; OC asoa = 1.8 PCM/PM 10 = 49% Natural PCM/PM 10 = 35% PCM/PM 10 = 38% Natural PCM/PM 10 = 19%

12. SORGA - Relative cont. of carb. matter to PM 10 (Winter) Hurdal (RB) PM 10 PM 10 = 4.2 µg m -3 Oslo (UB) PM 10 PM 10 = 9.5 µg m -3 Conversion factors: OC bsoa = 1.8; OC pb = 1.6; OC bb = 2.0; EC bb and EC ff = 1.1; OC ff = 1.3; OC asoa = 1.8 PCM/PM 10 = 45% Natural PCM/PM 10 = 3% PCM/PM 10 = 54% Natural PCM/PM 10 = 3%

13. SORGA - Measured vs modelled conc. of OCbsoa (Oslo, summer) OCp (PM 10 ) 3.2 ± 1.1 µg C m -3 OCbsoa 0.8-1.2 µg C m -3 OCbsoa modeled 0.2 ± 0.3 µg C m -3 OCp (PM 1 ) 1.8 ± 0.7 µg C m -3

14. SORGA - Measured vs modelled conc. of OCbsoa (Hurdal, winter) OCp (PM 10 ) 3.0 ± 1.2 µg C m -3 OCbsoa 1.0-1.5 µg C m -3 OCbsoa modeled 0.3 ± 0.3 µg m -3 OCp (PM 1 ) 1.4 ± 1.0 µg C m -3

15. SORGA - Summary of findings (1) The combined effort of 14 C, TOA, and organic tracer analysis is a powerful tool to explore various sources of carbonaceous matter OC bsoa was the major carbonaceous fraction in summer regardless of site and size fraction OC bb was the major carbonaceous fraction in winter regardsless of site and size fraction EC ff is the major contributor to EC regardless of season and size fraction Secondary organic aerosols vs primary carbonaceous aerosols Summer: Rural background site: SOA > PCA Urban background site: SOA ≤ PCA Winter: Rural and urban site: SOA << PCA

16. SORGA - Summary of findings (2) Anthropogenic vs natural sources of carbonaceous matter Urban background site: Summer: Natural >> Anthropogenic Winter: Natural << Anthropogenic Rural background site: Summer: Natural < Anthropogenic Winter: Natural << Anthropogenic