Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 9 1 2009 10.5194/acpd-9-1669-2009 http://www.atmos-chem-phys-discuss.net/9/1669/2009/ http://www.atmos-chem-phys-discuss.net/9/1669/2009/acpd-9-1669-2009.html http://www.atmos-chem-phys-discuss.net/9/1669/2009/acpd-9-1669-2009.pdf 1669 1702 2009-01-16 Increased cloud activation potential of secondary organic aerosol for atmospheric mass loadings S. M. King T. Rosenoern J. E. Shilling Q. Chen S. T. Martin scot_martin@harvard.edu School of Engineering and Applied Sciences & Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, USA now at: Pacific Northwest National Laboratory, Atmospheric Sciences and Global Change Division, Richland, WA 99352, USA The effect of organic particle mass loading from 1 to ≥100 μg m^−3 on the cloud condensation nuclei (CCN) properties of mixed organic-sulfate particles was investigated in the Harvard Environmental Chamber. Mixed particles were produced by the condensation of organic molecules onto ammonium sulfate particles during the dark ozonolysis of α-pinene. A continuous-flow mode of the chamber provided stable conditions over long time periods, allowing for signal integration and hence increased measurement precision at low organic mass loadings representative of atmospheric conditions. CCN activity was measured at eight mass loadings for 80- and 100-nm particles grown on 50-nm sulfate seeds. A two-component (organic/sulfate) Köhler model, which included the particle heterogeneity arising from DMA size selection and from organic volume fraction for the selected 80- and 100-nm particles, was used to predict CCN activity. For organic mass loadings of 2.9 μg m^−3 and greater, the observed activation curves were well predicted using a single set of physicochemical parameters for the organic component. For mass loadings of 1.74 μg m^−3 and less, the observed CCN activity increased beyond predicted values using the same parameters, implying changed physicochemical properties of the organic component. Of possible changes in surface tension, effective molecular weight, and effective density, a sensitivity analysis implicated a decrease of up to 10% in surface tension at low mass loadings as the plausible dominant mechanism for the observed increase in CCN activity. Alofs,~D J. and Balakumar,~P.: Inversion to obtain aerosol size distributions from measurements with a~differential mobility analyzer, J Aerosol Sci., 13, 513–527, 1982. Cocker,~D R., Clegg,~S L., Flagan,~R C., and Seinfeld,~J H.: The effect of water on gas-particle partitioning of secondary organic aerosol. Part I: $\alpha $-pinene/ozone system, Atmos. Environ., 35, 6049–6072, 2001a. Cocker,~D R., Flagan,~R C., and Seinfeld,~J H.: State-of-the-art chamber facility for studying atmospheric aerosol chemistry, Environ. Sci. Technol., 35, 2594–2601, 2001b. Collins,~D R., Flagan,~R C., and Seinfeld,~J H.: Improved inversion of scanning DMA data, Aerosol Sci. Technol., 36, 1–9, 2002. DeCarlo,~P F., Slowik,~J G., Worsnop,~D R., Davidovits,~P., and Jimenez,~J L.: Particle morphology and density characterization by combined mobility and aerodynamic diameter measurements. Part 1: Theory, Aerosol Sci. Technol., 38, 1185–1205, 2004. DeCarlo,~P F., Kimmel,~J R., Trimborn,~A., Northway,~M J., Jayne,~J T., Aiken,~A C., Gonin,~M., Fuhrer,~K., Horvath,~T., Docherty,~K S., Worsnop,~D R., and Jimenez,~J L.: Field-deployable, high-resolution, time-of-flight aerosol mass spectrometer, Anal. Chem., 78, 8281–8289, 2006. Donahue,~N M., Robinson,~A L., Stanier,~C O., and Pandis,~S N.: Coupled partitioning, dilution, and chemical aging of semivolatile organics, Environ. Sci. Technol., 40, 2635–2643, 2006. Duplissy,~J., Gysel,~M., Alfarra,~M R., Dommen,~J., Metzger,~A., Prevot,~A S H., Weingartner,~E., Laaksonen,~A., Raatikainen,~T., Good,~N., Turner,~S F., McFiggans,~G., and Baltensperger,~U.: Cloud forming potential of secondary organic aerosol under near atmospheric conditions, Geophys. Res. Lett., 35, L03818, doi:03810.01029/02007GL031075, 2008. Engelhart,~G J., Asa-Awuku,~A., Nenes,~A., and Pandis,~S N.: CCN activity and droplet growth kinetics of fresh and aged monoterpene secondary organic aerosol, Atmos. Chem. Phys., 8, 3937–3949, 2008. Ervens,~B., Feingold,~G., and Kreidenweis,~S M.: Influence of water-soluble organic carbon on cloud drop number concentration, J Geophys. Res., 110, D18211, doi:18210.11029/12004JD005634, 2005. Facchini,~M C., Mircea,~M., Fuzzi,~S., and Charlson,~R J.: Cloud albedo enhancement by surface-active organic solutes in growing droplets, Nature, 401, 257–259, 1999. Grieshop,~A P., Donahue,~N M., and Robinson,~A L.: Is the gas-particle partitioning in alpha-pinene secondary organic aerosol reversible?, Geophys. Res. Lett., 34, L14810, doi:14810.11029/12007GL029987, 2007. Hartz,~K E H., Rosenoern,~T., Ferchak,~S R., Raymond,~T M., Bilde,~M., Donahue,~N M., and Pandis,~S N.: Cloud condensation nuclei activation of monoterpene and sesquiterpene secondary organic aerosol, J Geophys. Res., 110, D14208, doi:14210.11029/12004JD005754, 2005. Hegg,~D A., Gao,~S., Hoppel,~W., Frick,~G., Caffrey,~P., Leaitch,~W R., Shantz,~N., Ambrusko,~J., and Albrechcinski,~T.: Laboratory studies of the efficiency of selected organic aerosols as CCN, Atmos. Res., 58, 155–166, 2001. IPCC (Intergovernmental Panel on Climate Change): Climate Change 2007: The Physical Science Basis, Cambridge University Press, 2007. Katrib,~Y., Martin,~S T., Rudich,~Y., Davidovits,~P., Jayne,~J T., and Worsnop,~D R.: Density changes of aerosol particles as a~result of chemical reaction, Atmos. Chem. Phys., 5, 275–291, 2005. King,~S M., Rosenoern,~T., Shilling,~J E., Chen,~Q., and Martin,~S T.: Cloud condensation nucleus activity of secondary organic aerosol particles mixed with sulfate, Geophys. Res. Lett., 34, L24803, doi:24810.21029/22007GL030390, 2007. Kleindienst,~T E., Smith,~D F., Li,~W., Edney,~E O., Driscoll,~D J., Speer,~R E., and Weathers,~W S.: Secondary organic aerosol formation from the oxidation of aromatic hydrocarbons in the presence of dry submicron ammonium sulfate aerosol, Atmos. Environ., 33, 3669–3681, 1999. Knutson,~E O. and Whitby,~T B.: Aerosol classification by electric mobility: Apparatus, theory, and applications, J Aerosol Sci., 6, 443–451, 1975. Kostenidou,~E., Pathak,~R K., and Pandis,~S N.: An algorithm for the calculation of secondary organic aerosol density combining AMS and SMPS data, Aerosol Sci. Technol., 41, 1002–1010, 2007. Lance,~S., Medina,~J., Smith,~J N., and Nenes,~A.: Mapping the operation of the DMT Continuous Flow CCN counter, Aerosol Sci. Technol., 40, 242–254, 2006. Lohmann,~U. and Feichter,~J.: Global indirect aerosol effects: a~review, Atmos. Chem. Phys., 5, 715–737, 2005. McFiggans,~G., Artaxo,~P., Baltensperger,~U., Coe,~H., Facchini,~M C., Feingold,~G., Fuzzi,~S., Gysel,~M., Laaksonen,~A., Lohmann,~U., Mentel,~T F., Murphy,~D M., O'Dowd,~C D., Snider,~J R., and Weingartner,~E.: The effect of physical and chemical aerosol properties on warm cloud droplet activation, Atmos. Chem. Phys., 6, 2593–2649, 2006. Paulsen,~D., Dommen,~J., Kalberer,~M., Prevot,~A S H., Richter,~R., Sax,~M., Steinbacher,~M., Weingartner,~E., and Baltensperger,~U.: Secondary organic aerosol formation by irradiation of 1,3,5-trimethylbenzene-\chemNO_x-\chemH_2O in a~new reaction chamber for atmospheric chemistry and physics, Environ. Sci. Technol., 39, 2668–2678, 2005. Petters,~M D. and Kreidenweis,~S M.: A~single parameter representation of hygroscopic growth and cloud condensation nucleus activity, Atmos. Chem. Phys., 7, 1961–1971, 2007. Petters,~M D., Prenni,~A J., Kreidenweis,~S M., and DeMott,~P J.: On measuring the critical diameter of cloud condensation nuclei using mobility selected aerosol, Aerosol Sci. Technol., 41, 907–913, 2007. Prenni,~A J., Petters,~M D., Kreidenweis,~S M., and DeMott,~P J.: Cloud droplet activation of secondary organic aerosol, J Geophys. Res., 112, D10223, doi:10210.11029/12006JD007963, 2007. Roberts,~G C. and Nenes,~A.: A~continuous-flow streamwise thermal-gradient CCN chamber for atmospheric measurements, Aerosol Sci. Technol., 39, 206–221, 2005. Rose,~D., Frank,~G P., Dusek,~U., Gunthe,~S S., Andreae,~M O., and Poschl,~U.: Calibration and measurement uncertainties of a~continuous-flow cloud condensation nucleus counter (DMT-CCNC): CCN activation of ammonium sulfate and sodium chloride aerosol particles in theory and experiment, Atmos. Chem. Phys., 8, 1153–1179, 2008. Seinfeld,~J H., Kleindienst,~T E., Edney,~E O., and Cohen,~J B.: Aerosol growth in a~steady-state, continuous flow chamber: Application to studies of secondary aerosol formation, Aerosol Sci. Technol., 37, 728–734, 2003. Seinfeld,~J H. and Pankow,~J F.: Organic Atmospheric Particulate Material, Annu. Rev. Phys. Chem., 54, 121–140, 2003. Shilling,~J E., King,~S M., Mochida,~M., Worsnop,~D R., and Martin,~S T.: Mass spectral evidence that small changes in composition caused by oxidative aging processes alter aerosol CCN properties, J Phys. Chem. A, 111, 3358–3368, 2007. Shilling,~J E., Chen,~Q., King,~S M., Rosenoern,~T., Kroll,~J H., Worsnop,~D R., DeCarlo,~P F., Aiken,~A C., Sueper,~D., Jimenez,~J L., and Martin,~S T.: Loading-dependent elemental composition of $\alpha $-pinene SOA particles, Atmos. Chem. Phys. Discuss., 8, 15343–15373, 2008a. Shilling,~J E., Chen,~Q., King,~S M., Rosenoern,~T., Kroll,~J H., Worsnop,~D R., McKinney,~K A., and Martin,~S T.: Particle mass yield in secondary organic aerosol formed by the dark ozonolysis of $\alpha $-pinene, Atmos. Chem. Phys., 8, 2073–2088, 2008b. Stanier,~C O., Pathak,~R K., and Pandis,~S N.: Measurements of the volatility of aerosols from $\alpha $-pinene ozonolysis, Environ. Sci. Technol., 41, 2756–2763, 2007. Svenningsson,~B., Rissler,~J., Swietlicki,~E., Mircea,~M., Bilde,~M., Facchini,~M C., Decesari,~S., Fuzzi,~S., Zhou,~J., Mønster,~J., and Rosenoern,~T.: Hygroscopic growth and critical supersaturations for mixed aerosol particles of inorganic and organic compounds of atmospheric relevance, Atmos. Chem. Phys., 6, 1937–1952, 2006. VanReken,~T M., Ng,~N L., Flagan,~R C., and Seinfeld,~J H.: Cloud condensation nucleus activation properties of biogenic secondary organic aerosol, J Geophys. Res., 110, D07206, doi:07210.01029/02004JD005465, 2005. Wiedensohler,~A.: An approximation of the bipolar charge distribution for particles in the submicron size range, J Aerosol Sci., 19, 387–389, 1988.