1. P. Schlag 1,2, A. Vermeulen 3, M. J. Blom 3, A. Kiendler-Scharr 2,A. Khan 1, R. Holzinger 1 1 Institute for Marine and Atmospheric research Utrecht (IMAU), Utrecht University, The Netherlands 2 Institut für Energie- and Klimaforschung: Troposphäre (IEK-8), Forschungszentrum Jülich GmbH, Germany 3 Energieonderzoek Centrum Nederland (ECN), The Netherlands Chemical air speciation at Cabauw, NL

2. Cabauw Experimental Site for Atmospheric Research (CESAR)

3. November 2011: AMS, TD-PTR-MS May-July 2012: AMS, TD-PTR-MS, MARGA July 2012 – June 2013: ACSM Jan-Feb 2013:PTR-MS, ACSM Campaigns: AMS, ACSM:vaporization (600°C), electron ionization TD-PTR-MS: thermal desorption (50-350°C) Chemical ionization (H 3 O + ) MARGA:liquid chromatography

4. Instrument Comparison: AMS, ACMS, MARGA, TD-PTR-MS Correlation slopes HR-ToF-AMS vs.ACSM vs. MARGA 0.60 (R 2 =0.92) 0.60 (R 2 =0.93) 0.55 (R 2 =0.84) 0.50 (R 2 =0.83) (422 data points) 1.23 (R 2 =0.96) 0.88 (R 2 =0.93) 0.63 (R 2 =0.86) 0.49 (R 2 =0.26) (1943 data points) ACSM 1.03 (R 2 =0.73) 0.85 (R 2 =0.89) 1.22 (R 2 =0.71) 2.04 (R 2 =0.76) 1.49 (R 2 =0.31) (289 data points) Organics Nitrate Ammonium Sulphate Chloride (No. of points)

5. ACSM: Campaign Overview July 2012 to June 2013 Total average mass loading: 9.6 µg/m 3

6.  12 exceedances of WHO PM 2.5 daily mean limit Total PM 1 mass: Daily means Whole year Org NO 3 SO 4 NH 3 Chl BC

7. PMF results from ACSM data – Winter 2013

8. Zeppelin in the Netherlands Time series of fractional species contribution to PM 1 mass (a), excess NH 4 (b), and species mass concentration (c) ToF-AMS: Ground based measurements May-July 2012 excess NH 4 : 4+ = 4+ − (3− + − + 2 ∙ 42− )

9. N/C=15% (AMS 3%) N/C=6% N/C=4% N/C=9% (AMS 2%) N/C=2% (AMS 0%) N/C=4% (AMS 1%)

10. Actris/EMEP winter campaign Jan/Feb 2012 Cabauw, PTR-MS, aromatics young traffic plumes Aged traffic plumes No biomass burning: acetonitrile always below 0.05 nmol/mol

11. Actris/EMEP winter campaign Jan/Feb 2012 Cabauw, PTR-MS, aromatics 2 young traffic plumes Aged traffic plumes

12. Actris/EMEP winter campaign Jan/Feb 2012 Cabauw, PTR-MS, Oxygenated species young traffic plumes Aged traffic plumes

13. Actris/EMEP winter campaign Jan/Feb 2012 Cabauw, PTR-MS, isoprene, MVK+MACR, monoterp. young traffic plumes Aged traffic plumes

14. Actris/EMEP winter campaign Jan/Feb 2012 Cabauw, PTR-MS, others (naphtalene, org. acids) young traffic plumes Aged traffic plumes Different air mass origin?

15. Summary ◘ Intercomparison: AMS, ACSM, MARGA, TD-PTR-MS ◘ 1-year ACSM measurements in Cabauw: 12 exceedances of WHO PM 2.5 daily limit Nitrate and organics are the most dominant species ◘ TD-PTR-MS factor analysis (PMF) suggests high N/C ratios of OA components Link to AMS observations of excess NH 4 at Cabauw ◘ Gas phase PTR-MS: full mass spectrum monitoring of organics at levels below 0.01 nmol/mol Tool for online monitoring of the semivolatile gas phase burden.