Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 9 5 2009 10.5194/acpd-9-21237-2009 http://www.atmos-chem-phys-discuss.net/9/21237/2009/ http://www.atmos-chem-phys-discuss.net/9/21237/2009/acpd-9-21237-2009.html http://www.atmos-chem-phys-discuss.net/9/21237/2009/acpd-9-21237-2009.pdf 21237 21256 2009-10-09 CCN predictions using simplified assumptions of organic aerosol composition and mixing state: a synthesis from six different locations B. Ervens barbara.ervens@noaa.gov M. J. Cubison E. Andrews G. Feingold J. A. Ogren J. L. Jimenez P. K. Quinn T. S. Bates J. Wang Q. Zhang H. Coe M. Flynn J. D. Allan Cooperative Institute for Research in Environmental Science (CIRES), University of Colorado, Boulder, CO, USA NOAA Earth System Research Laboratory, Boulder, CO, USA Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, USA NOAA Pacific Marine Environmental Laboratory, Seattle, WA, USA Brookhaven National Laboratory, 75 Rutherford Drive, Upton, NY, USA Department of Environmental Toxicology, University of California, Davis, CA, USA School of Earth, Atmospheric and Environmental Science, The University of Manchester, UK National Centre for Atmospheric Science, School of Earth, Atmospheric & Environmental Sciences, The University of Manchester, Manchester, UK An accurate but simple quantification of the fraction of aerosol particles that can act as cloud condensation nuclei (CCN) is needed for implementation in large-scale models. Data on aerosol size distribution, chemical composition, and CCN concentration from six different locations have been analyzed to explore the extent to which simple assumptions of composition and mixing state of the organic fraction can reproduce measured CCN number concentrations. <br><br> Fresher pollution aerosol as encountered in Riverside, CA, and the ship channel in Houston, TX, cannot be represented without knowledge of more complex (size-resolved) composition. For aerosol that has experienced processing (Mexico City, Holme Moss (UK), Point Reyes (CA), and Chebogue Point (Canada)), CCN can be predicted within a factor of two assuming either externally or internally mixed soluble organics although these simplified compositions/mixing states might not represent the actual properties of ambient aerosol populations. Under typical conditions, a factor of two uncertainty in CCN concentration translates to an uncertainty of ~15% in cloud drop concentration, which might be adequate for large-scale models given the much larger uncertainty in cloudiness. Bahreini,~R., Ervens,~B., Middlebrook,~A M., Warneke,~C., DeGouw,~J A., DeCarlo,~P., Jimenez,~J L., Brock,~C A., Neuman,~J A., Ryerson,~T B., Stark,~H., Atlas,~E., Brioude,~J., Fried,~A., Holloway,~J S., Peischl,~J., Richter,~D., Walega,~J., Weibring,~P., Wollny,~A G., and Fehsenfeld,~F C.: Organic aerosol formation in urban and industrial plumes in Houston, TX, J Geophys. Res., 114, D00F16, doi:10.1029/2008JD011493, 2009. Bates,~T S., Quinn,~P K., Coffman,~D., Schulz,~K., Covert,~D S., Johnson,~J E., Williams,~E J., Lerner,~B M., Angevine,~W M., Tucker,~S C., Brewer,~W A., and Stohl,~A.: Boundary layer aerosol chemistry during TexAQS/GoMACCS 2006: insights into aerosol sources and transformation processes, J Geophys. Res., 113, D00F01, doi:10.1029/2008JD010023, 2008. Bilde,~M. and Svenningsson,~B.: CCN activation of slightly soluble organics: the importance of small amounts of inorganic salt and particle phase, Tellus, 56B, 128–134, 2004. Canagaratna,~M R., Jayne,~J T., Jimenez,~J L., Allan,~J D., Alfarra,~M R., Zhang,~Q., Onasch,~T B., Drewnick,~F., Coe,~H., Middlebrook,~A., Delia,~A., Williams,~L R., Trimborn,~A M., Northway,~M J., DeCarlo,~P F., Kolb,~C E., Davidovits,~P., and Worsnop,~D R.: Chemical and microphysical characterization of ambient aerosols with the Aerodyne Aerosol Mass Spectrometer, Mass Spectrom. Rev., 26, 185–222, 2007. Conant,~W C., VanReken,~T M., Rissman,~T A., Varutbangkul,~V., Jonsson,~H H., Nenes,~A., Jimenez,~J L., Delia,~A E., Bahreini,~R., Roberts,~G C., Flagan,~R C., and Seinfeld,~J H.: Aerosol-cloud drop concentration closure in warm cumulus, J Geophys. Res., 109, D13204, doi:10.1029/2003JD004324, 2004. Corrigan,~C E. and Novakov,~T.: Cloud condensation nucleus activity of organic compounds: a~laboratory study, Atmos. Environ., 33, 2661–2668, 1999. Corris, B.: Atmospheric aerosol: The link between composition and physical behavior, PhD Thesis, School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester (UK), 2008. Cruz,~C N. and Pandis,~S N.: Deliquescence and hygroscopic growth of mixed inorganic-organic atmospheric aerosols, Environ. Sci. Technol., 34, 4313–4319, 2000. Cubison,~M J., Ervens,~B., Feingold,~G., Docherty,~K S., Ulbrich,~I M., Shields,~L., Prather,~K., Hering,~S., and Jimenez,~J L.: The influence of chemical composition and mixing state of Los Angeles urban aerosol on CCN number and cloud properties, Atmos. Chem. Phys., 8, 5649–5667, 2008. DeGouw,~J. and Jimenez,~J L.: Organic aerosols in the Earth's atmosphere: organic particles are abundant in the troposphere and important for air quality and climate – but what are their sources?, Environ. Sci. Technol., in press, 2009. Dusek,~U., Frank,~G P., Hildebrandt,~L., Curtius,~J., Schneider,~J., Walter,~S., Chand,~D., Drewnick,~F., Hings,~S., Jung,~D., Borrmann,~S., and Andreae,~M O.: Size matters more than chemistry for cloud-nucleating ability of aerosol particles, Science, 312, 1375–1378, 2006. Ervens,~B., Feingold,~G., and Kreidenweis,~S M.: The influence of water-soluble organic carbon on cloud drop number concentration, J Geophys. Res., 110, D18211, doi:10.1029/2004JD005634, 2005. Ervens,~B., Cubison,~M J., Andrews,~E., Feingold,~G., Ogren,~J A., Jimenez,~J L., DeCarlo,~P., and Nenes,~A.: Prediction of cloud condensation nucleus number concentration using measurements of aerosol size distributions and composition and light scattering enhancement due to humidity, J Geophys. Res., 112, D10532, doi:10.1029/2006JD007426, 2007. Furutani,~H., Dall'osto,~M., Roberts,~G C., and Prather,~K A.: Assessment of the relative importance of atmospheric ageing on CCN activity derived from field observations, Atmos. Environ., 42, 3130–3142, 2008. Holzinger,~R., Milet,~D B., Williams,~B., Lee,~A., Kreisberg,~N., Hering,~S V., Jimenez,~J L., Allan,~J D., Worsnop,~D R., and Goldstein,~A H.: Emission, oxidation, and secondary organic aerosol formation of volatile organic compounds as observed at Chebogue Point, Nova Scotia, J Geophys. Res., 112, D10524, doi:10.1029/2006JD007599, 2007. Mircea,~M., Facchini,~M C., Decesari,~S., Cavalli,~F., Emblico,~L., Fuzzi,~S., Vestin,~A., Rissler,~J., Swietlicki,~E., Frank,~G., Andreae,~M O., Maenhaut,~W., Rudich,~Y., and Artaxo,~P.: Importance of the organic aerosol fraction for modeling aerosol hygroscopic growth and activation: a~case study in the Amazon Basin, Atmos. Chem. Phys., 5, 3111–3126, 2005. Moffet,~R C., de Foy,~B., Molina,~L T., Molina,~M J., and Prather,~K A.: Measurement of ambient aerosols in northern Mexico City by single particle mass spectrometry, Atmos. Chem. Phys., 8, 4499–4516, 2008. Petters,~M D., Prenni,~A J., Kreidenweis,~S M., DeMott,~P J., Matsunaga,~A., Lim,~Y B., and Ziemann,~P J.: Chemical ageing and the hydrophobic-hydrophilic conversion of carbonaceous aerosol, Geophys. Res. Lett., 33, L24806, doi:10.1029/2006GL027249, 2006. 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. Pierce,~J R., Chen,~K., and Adams,~P J.: Contribution of primary carbonaceous aerosol to cloud condensation nuclei: processes and uncertainties evaluated with a global aerosol microphysics model, Atmos. Chem. Phys., 7, 5447–5466, 2007. Quinn,~P K., Bates,~T S., Coffman,~D J., and Covert,~D S.: Influence of particle size and chemistry on the cloud nucleating properties of aerosols, Atmos. Chem. Phys., 8, 1029–1042, 2008. Riemer,~N., West,~M., Zaveri,~R., and Easter,~R.: Estimating black carbon ageing time-scales with a~particle resolved aerosol model, J Aerosol Sci., in press, 2009. Spencer,~M T., Shields,~L G., and Prather,~K A.: Simultaneous measurements of the effective density and chemical composition of ambient aerosol particles, Environ. Sci. Technol., 41, 1303–1309, 2007. Stroud,~C., Nenes,~A., Jimenez,~J L., DeCarlo,~P., Huffman,~J A., Bruintjes,~R., Nemitz,~E., Delia,~A E., Toohey,~D W., Guenther,~A B., and Nandi,~S.: Cloud activating properties of aerosol observed during CELTIC, J Atmos. Sci., 64, 441–459, 2007. Twohy,~C H. and Anderson,~J R.: Droplet nuclei on non-precipitating clouds: composition and size matter, Environ. Res. Lett., 3(4), doi:10.1088/1748-9326/3/4/045002, 2008. Williams,~B J., Goldstein,~A H., Millet,~D B., Holzinger,~R., Kreisberg,~N M., Hering,~S V., White,~A B., Worsnop,~D R., Allan,~J D., and Jimenez,~J L.: Chemical speciation of organic aerosol during the International Consortium for Atmospheric Research on Transport and Transformation 2004: results from in situ measurements, J Geophys. Res., 112, D1026, doi:10.1029/2006JD007601, 2007. Wilson,~J., Cuvelier,~C., and Raes,~F.: A~modeling study of global mixed aerosol fields, J Geophys. Res., 106, 34081–34108, 2001.