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Source apportionment of the carbonaceous aerosol – Quantitative estimates based on 14 C - and organic tracer analysis. Bordeaux 23 - 25 April 2008. KE Yttri 1 , D Simpson 2 , H. Puxbaum 3 , K Stenström 4 , T Svendby 1. Norwegian Institute for Air Research Norwegian Meteorological Institute
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Source apportionment of the carbonaceous aerosol – Quantitative estimates based on 14C- and organic tracer analysis Bordeaux 23 - 25 April 2008 KE Yttri1, D Simpson2, H. Puxbaum3, K Stenström4, T Svendby1 • Norwegian Institute for Air Research • Norwegian Meteorological Institute • Technical University of Vienna • Lund University
SORGA - Main objectives • Quantifythecontributionofbiogenic and anthropogeniccarbonaceous matter to PM in the Nordic urban and rural environment • Biogenic/anthropogenicfraction in urban and rural areas • Separate thebiogenic and theanthropogenicfractionintoprimary and secondarycarbonaceous matter • Size-distribution (PM1 and PM10) ofbiogenic and anthropogeniccarboanceous matter • ImprovecurrentknowledgeofwhataretheconcentrationsofVOCscrucial for SOA-formation • Improvethe aerosol modulesofthefollowingmodels: • MAPS - EPISODE - EMEP
Hurdal Oslo Oslo (Urban background) Hurdal (Rural Background) SORGA - Measurements sites Measurement campaigns Summer period: 19 June - 5 July 2006Winter period: 1 - 8Mars 2007
SORGA - Aerosol parameters measured Table 1: Input parameters for source apportionment of the particulate carbonaceous fraction • Cellulose analysis performed at the Technical University of Vienna • 14C-analysisperformed at the University of Lund Yttri et al. in progress
SORGA - Sources of carbonaceous matter OCbbOC from residential wood burning ECbbEC from residential wood burning OCffOC from combustion of fossil fuel ECffEC from combustion of fossil fuel OCpbs OC from fungal spores OCpbcOC from plant debris OCbsoaOC from biogenic sec. org. aerosols OCasoaOC from anthropogenic sec. org. aerosols
SORGA - Equations and uncertainty estimates Table 2: Low, central and high factors used to estimate the carbonaceous subfractions using LHS Equations to calculate carbonaceous subfractions Confounding factors OCbsoa: OCnf OCbsoa, OCmeat cooking, condensation of SVOC from biomass(?), PBAP not accounted for by sugars and sugar-alcohols
SORGA - Source apportionment of TCp in PM10 Summer Hurdal (RB) PM10 TCp = 2.9 ± 1.2 µg C m-3 Oslo (UB) PM10 TCp = 3.7 ± 1.3 µg C m-3 Natural: 72% Anthropogenic: 28% Natural: 46% Anthropogenic: 54%
SORGA - Source apportionment of TCp in PM1, Summer Hurdal (RB) PM1 TCp = 1.7 ± 1.1 µg C m-3 Oslo (UB) PM1 TCp = 2.3 ± 0.8 µg C m-3 Natural: 66% Anthropogenic: 34% Natural: 36% Anthropogenic: 64%
SORGA - Source apportionment of TCp in PM10 Winter Hurdal (RB) PM10 TCp = 1.2 ± 0.5 µg C m-3 Oslo (UB) PM10 TCp = 3.2 ± 1.5 µg C m-3 Natural: 8% Anthropogenic: 92% Natural: 5% Anthropogenic: 95%
-3 SORGA - Source apportionment of TCp in PM10 Summer Day/night variation Oslo(UB) PM10DAY TCp = 3.8 ± 1.2 µg C m-3 Oslo (UB) PM10NIGHT TCp = 3.6 ± 1.4 µg C m-3 Natural: 52% Anthropogenic:48% Natural: 40% Anthropogenic:60%
SORGA - Relative cont. of carb. matter to PM10 (Summer) Oslo (UB) PM10 PM10 = 15.6 µg m-3 Hurdal (RB) PM10PM10 = 10.4 µg m-3 PCM/PM10 = 38% Natural PCM/PM10 = 19% PCM/PM10 = 49% Natural PCM/PM10 = 35% Conversion factors: OCbsoa = 1.8; OCpb = 1.6; OCbb = 2.0; ECbb and ECff = 1.1; OCff = 1.3; OCasoa = 1.8
SORGA - Relative cont. of carb. matter to PM10 (Winter) Oslo (UB) PM10 PM10 = 9.5 µg m-3 Hurdal (RB) PM10PM10 = 4.2 µg m-3 PCM/PM10 = 54% Natural PCM/PM10 = 3% PCM/PM10 = 45% Natural PCM/PM10 = 3% Conversion factors: OCbsoa = 1.8; OCpb = 1.6; OCbb = 2.0; ECbb and ECff = 1.1; OCff = 1.3; OCasoa = 1.8
SORGA - Measured vs modelled conc. of OCbsoa (Oslo, summer) OCp (PM10) 3.2 ± 1.1 µg C m-3 OCp (PM1) 1.8 ± 0.7 µg C m-3 OCbsoa 0.8-1.2 µg C m-3 OCbsoa modeled 0.2 ± 0.3 µg C m-3
SORGA - Measured vs modelled conc. of OCbsoa (Hurdal, winter) OCp (PM10) 3.0 ± 1.2 µg C m-3 OCp (PM1) 1.4 ± 1.0 µg C m-3 OCbsoa 1.0-1.5 µg C m-3 OCbsoa modeled 0.3 ± 0.3 µg m-3
SORGA - Summary of findings (1) • The combined effort of 14C, TOA, and organic tracer analysis is a powerful tool to explore various sources of carbonaceous matter • OCbsoa was the major carbonaceous fraction in summer regardless of site and size fraction • OCbb was the major carbonaceous fraction in winter regardsless of site and size fraction • ECff 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
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