ACPD Atmospheric Chemistry and Physics Discussions ACPD Atmos. Chem. Phys. Discuss. 1680-7375 Göttingen, Germany 10.5194/acpd-13-3419-2013 Investigation of the connections between atmospheric new particle formation and organics at an urban site of Beijing Wang Z. B. 1 2 Hu M. https://orcid.org/0000-0003-4816-9123 1 Wu Z. J. 1 2 Yue D. L. 1 Zheng J. 3 Zhang R. Y. 1 3 Pei X. Y. 4 Paasonen P. https://orcid.org/0000-0002-4625-9590 4 5 Dal Maso M. 4 Boy M. 4 Wiedensohler A. https://orcid.org/0000-0001-8298-491X 2 State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China Leibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, Germany Department of Atmospheric Science, Texas A&M University, College Station, Texas 77843, USA Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland International Institute for Applied Systems Analysis, Schlossplatz 1, 2361 Laxenburg, Austria 06 02 2013 13 2 3419 3450 Copyright: © 2013 Z. B. Wang et al. 2013 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://acp.copernicus.org/preprints/13/3419/2013/acpd-13-3419-2013.html The full text article is available as a PDF file from https://acp.copernicus.org/preprints/13/3419/2013/acpd-13-3419-2013.pdf

The role of low-volatility organic vapors in atmospheric new particle formation has been studied based on a data set of 17 nucleation events observed during the CAREBeijing 2008 campaign. The particle formation rates show good correlations with sulfuric acid and organic vapors implying that both play an important role in the atmospheric new particle formation. High correlation coefficients are observed in all investigated nucleation mechanisms. The best fit (<i>R</i> = 0.73, slope = 1.1) between the observed and modelled particle formation rates is achieved with the homogenous nucleation theory of sulfuric acid (both homomolecularly and hetermolecularly) with separate coefficients in <i>J=K</i><sub>SA1</sub>[H<sub>2</sub>SO<sub>4</sub>]<sup>2</sup>+<i>K</i><sub>SA2</sub>[H<sub>2</sub>SO<sub>4</sub>][Org]. The contributions of the sulfuric acid and the organics involving terms have been 43% and 57%, respectively. In addition, the higher particle formation rates are observed on polluted nucleation days, indicating the organic vapors should be involved in the new particle formation process in the polluted urban environment of Beijing with high background aerosol loading.

 References Berndt,&nbsp;T., Boge,&nbsp;O., Stratmann,&nbsp;F., Heintzenberg,&nbsp;J., and Kulmala,&nbsp;M.: Rapid formation of sulfuric acid particles at near-atmospheric conditions, Science, 307, 698–700, 2005. Birmili,&nbsp;W., Stratmann,&nbsp;F., and Wiedensohler,&nbsp;A.: Design of a&nbsp;DMA-based size spectrometer for a&nbsp;large particle size range and stable operation, J. Aerosol Sci., 30, 549–553, 1999. Boy,&nbsp;M., Kulmala,&nbsp;M., Ruuskanen,&nbsp;T.&nbsp;M., Pihlatie,&nbsp;M., Reissell,&nbsp;A., Aalto,&nbsp;P.&nbsp;P., Keronen,&nbsp;P., Dal&nbsp;Maso,&nbsp;M., Hellen,&nbsp;H., Hakola,&nbsp;H., Jansson,&nbsp;R., Hanke,&nbsp;M., and Arnold,&nbsp;F.: Sulphuric acid closure and contribution to nucleation mode particle growth, Atmos. Chem. Phys., 5, 863–878, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-5-863-2005">10.5194/acp-5-863-2005</a>, 2005. Chen,&nbsp;M., Titcombe,&nbsp;M., Jiang,&nbsp;J., Jen,&nbsp;C., Kuang,&nbsp;C., Fischer,&nbsp;M.&nbsp;L., Eisele,&nbsp;F.&nbsp;L., Siepmann,&nbsp;J.&nbsp;I., Hanson,&nbsp;D.&nbsp;R., Zhao,&nbsp;J., and McMurry,&nbsp;P.&nbsp;H.: Acid–base chemical reaction model for nucleation rates in the polluted atmospheric boundary layer, P. Natl. Acad. Sci. USA, 109, 18713–18718, 2012. Donahue, N. M., Trump, E. R., Pierce, J. R., and Riipinen, I.: Theoretical constraints on pure vapor-pressure driven condensation of organics to ultrafine particles, Geophys. Res. Lett., 38, L16801, <a href="http://dx.doi.org/10.1029/2011gl048115">https://doi.org/10.1029/2011gl048115</a>, 2011. Fiedler,&nbsp;V., Dal&nbsp;Maso,&nbsp;M., Boy,&nbsp;M., Aufmhoff,&nbsp;H., Hoffmann,&nbsp;J., Schuck,&nbsp;T., Birmili,&nbsp;W., Hanke,&nbsp;M., Uecker,&nbsp;J., Arnold,&nbsp;F., and Kulmala,&nbsp;M.: The contribution of sulphuric acid to atmospheric particle formation and growth: a&nbsp;comparison between boundary layers in Northern and Central Europe, Atmos. Chem. Phys., 5, 1773–1785, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-5-1773-2005">10.5194/acp-5-1773-2005</a>, 2005. Hallquist,&nbsp;M., Wenger,&nbsp;J.&nbsp;C., Baltensperger,&nbsp;U., Rudich,&nbsp;Y., Simpson,&nbsp;D., Claeys,&nbsp;M., Dommen,&nbsp;J., Donahue,&nbsp;N.&nbsp;M., George,&nbsp;C., Goldstein,&nbsp;A.&nbsp;H., Hamilton,&nbsp;J.&nbsp;F., Herrmann,&nbsp;H., Hoffmann,&nbsp;T., Iinuma,&nbsp;Y., Jang,&nbsp;M., Jenkin,&nbsp;M.&nbsp;E., Jimenez,&nbsp;J.&nbsp;L., Kiendler-Scharr,&nbsp;A., Maenhaut,&nbsp;W., McFiggans,&nbsp;G., Mentel,&nbsp;Th.&nbsp;F., Monod,&nbsp;A., Prévôt,&nbsp;A.&nbsp;S.&nbsp;H., Seinfeld,&nbsp;J.&nbsp;H., Surratt,&nbsp;J.&nbsp;D., Szmigielski,&nbsp;R., and Wildt,&nbsp;J.: The formation, properties and impact of secondary organic aerosol: current and emerging issues, Atmos. Chem. Phys., 9, 5155–5236, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-9-5155-2009">10.5194/acp-9-5155-2009</a>, 2009. Hao,&nbsp;L.&nbsp;Q., Yli-Pirilä,&nbsp;P., Tiitta,&nbsp;P., Romakkaniemi,&nbsp;S., Vaattovaara,&nbsp;P., Kajos,&nbsp;M.&nbsp;K., Rinne,&nbsp;J., Heijari,&nbsp;J., Kortelainen,&nbsp;A., Miettinen,&nbsp;P., Kroll,&nbsp;J.&nbsp;H., Holopainen,&nbsp;J.&nbsp;K., Smith,&nbsp;J.&nbsp;N., Joutsensaari,&nbsp;J., Kulmala,&nbsp;M., Worsnop,&nbsp;D.&nbsp;R., and Laaksonen,&nbsp;A.: New particle formation from the oxidation of direct emissions of pine seedlings, Atmos. Chem. Phys., 9, 8121–8137, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-9-8121-2009">10.5194/acp-9-8121-2009</a>, 2009. Holmes,&nbsp;N.&nbsp;S.: A&nbsp;review of particle formation events and growth in the atmosphere in the various environments and discussion of mechanistic implications, Atmos. Environ., 41, 2183–2201, 2007. Kannosto,&nbsp;J., Virtanen,&nbsp;A., Lemmetty,&nbsp;M., Mäkelä,&nbsp;J.&nbsp;M., Keskinen,&nbsp;J., Junninen,&nbsp;H., Hussein,&nbsp;T., Aalto,&nbsp;P., and Kulmala,&nbsp;M.: Mode resolved density of atmospheric aerosol particles, Atmos. Chem. Phys., 8, 5327–5337, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-8-5327-2008">10.5194/acp-8-5327-2008</a>, 2008. Kerminen,&nbsp;V.-M., Petäjä,&nbsp;T., Manninen,&nbsp;H.&nbsp;E., Paasonen,&nbsp;P., Nieminen,&nbsp;T., Sipilä,&nbsp;M., Junninen,&nbsp;H., Ehn,&nbsp;M., Gagné,&nbsp;S., Laakso,&nbsp;L., Riipinen,&nbsp;I., Vehkamäki,&nbsp;H., Kurten,&nbsp;T., Ortega,&nbsp;I.&nbsp;K., Dal&nbsp;Maso,&nbsp;M., Brus,&nbsp;D., Hyvärinen,&nbsp;A., Lihavainen,&nbsp;H., Leppä,&nbsp;J., Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J., Mirme,&nbsp;A., Mirme,&nbsp;S., Hõrrak,&nbsp;U., Berndt,&nbsp;T., Stratmann,&nbsp;F., Birmili,&nbsp;W., Wiedensohler,&nbsp;A., Metzger,&nbsp;A., Dommen,&nbsp;J., Baltensperger,&nbsp;U., Kiendler-Scharr,&nbsp;A., Mentel,&nbsp;T.&nbsp;F., Wildt,&nbsp;J., Winkler,&nbsp;P.&nbsp;M., Wagner,&nbsp;P.&nbsp;E., Petzold,&nbsp;A., Minikin,&nbsp;A., Plass-Dülmer,&nbsp;C., Pöschl,&nbsp;U., Laaksonen,&nbsp;A., and Kulmala,&nbsp;M.: Atmospheric nucleation: highlights of the EUCAARI project and future directions, Atmos. Chem. Phys., 10, 10829–10848, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-10-10829-2010">10.5194/acp-10-10829-2010</a>, 2010. Kuang,&nbsp;C., McMurry,&nbsp;P.&nbsp;H., McCormick,&nbsp;A.&nbsp;V., and Eisele,&nbsp;F.&nbsp;L.: Dependence of nucleation rates on sulfuric acid vapor concentration in diverse atmospheric locations, J.&nbsp;Geophys. Res., 113, D10209, <a href="http://dx.doi.org/10.1029/2007jd009253">https://doi.org/10.1029/2007jd009253</a>, 2008. Kuang,&nbsp;C., McMurry,&nbsp;P.&nbsp;H., and McCormick,&nbsp;A.&nbsp;V.: Determination of cloud condensation nuclei production from measured new particle formation events, Geophys. Res. Lett., 36, L09822, <a href="http://dx.doi.org/10.1029/2009gl037584">https://doi.org/10.1029/2009gl037584</a>, 2009. Kuang,&nbsp;C., Riipinen,&nbsp;I., Sihto,&nbsp;S.-L., Kulmala,&nbsp;M., McCormick,&nbsp;A.&nbsp;V., and McMurry,&nbsp;P.&nbsp;H.: An improved criterion for new particle formation in diverse atmospheric environments, Atmos. Chem. Phys., 10, 8469–8480, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-10-8469-2010">10.5194/acp-10-8469-2010</a>, 2010. Kulmala,&nbsp;M.: How particles nucleate and grow, Science, 302, 1000–1001, 2003. Kulmala,&nbsp;M. and Kerminen,&nbsp;V.&nbsp;M.: On the formation and growth of atmospheric nanoparticles, Atmos. Res., 90, 132–150, 2008. Kulmala,&nbsp;M., Dal Maso,&nbsp;M., Makela,&nbsp;J.&nbsp;M., Pirjola,&nbsp;L., Vakeva,&nbsp;M., Aalto,&nbsp;P., Miikkulainen,&nbsp;P., Hameri,&nbsp;K., and O'Dowd,&nbsp;C.&nbsp;D.: On the formation, growth and composition of nucleation mode particles, Tellus&nbsp;B, 53, 479–490, 2001. Kulmala,&nbsp;M., Vehkamaki,&nbsp;H., Petaja,&nbsp;T., Dal Maso,&nbsp;M., Lauri,&nbsp;A., Kerminen,&nbsp;V.&nbsp;M., Birmili,&nbsp;W., and McMurry,&nbsp;P.&nbsp;H.: Formation and growth rates of ultrafine atmospheric particles: a&nbsp;review of observations, J.&nbsp;Aerosol Sci., 35, 143–176, 2004. Kulmala,&nbsp;M., Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J., and Laaksonen,&nbsp;A.: Cluster activation theory as an explanation of the linear dependence between formation rate of 3 <abbr>nm</abbr> particles and sulphuric acid concentration, Atmos. Chem. Phys., 6, 787–793, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-6-787-2006">10.5194/acp-6-787-2006</a>, 2006. Kulmala,&nbsp;M., Petäjä,&nbsp;T., Nieminen,&nbsp;T., Sipilä,&nbsp;M., Manninen,&nbsp;H.&nbsp;E., Lehtipalo,&nbsp;K., Dal Maso,&nbsp;M., Aalto,&nbsp;P.&nbsp;P., Junninen,&nbsp;H., Paasonen,&nbsp;P., Riipinen,&nbsp;I., Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J., Laaksonen,&nbsp;A., and Kerminen.&nbsp;V.-M.: Measurement of the nucleation of atmospheric aerosol particles, Nat. Protoc., 7, 1651–1667, 2012. Kurten,&nbsp;T., Torpo,&nbsp;L., Ding,&nbsp;C.&nbsp;G., Vehkamaki,&nbsp;H., Sundberg,&nbsp;M.&nbsp;R., Laasonen,&nbsp;K., and Kulmala,&nbsp;M.: A&nbsp;density functional study on water-sulfuric acid-ammonia clusters and implications for atmospheric cluster formation, J. Geophys. Res., 112, <a href="http://dx.doi.org/10.1029/2006jd007391">https://doi.org/10.1029/2006jd007391</a>, 2007. Laaksonen,&nbsp;A., Kulmala,&nbsp;M., O'Dowd,&nbsp;C.&nbsp;D., Joutsensaari,&nbsp;J., Vaattovaara,&nbsp;P., Mikkonen,&nbsp;S., Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J., Sogacheva,&nbsp;L., Dal&nbsp;Maso,&nbsp;M., Aalto,&nbsp;P., Petäjä,&nbsp;T., Sogachev,&nbsp;A., Yoon,&nbsp;Y.&nbsp;J., Lihavainen,&nbsp;H., Nilsson,&nbsp;D., Facchini,&nbsp;M.&nbsp;C., Cavalli,&nbsp;F., Fuzzi,&nbsp;S., Hoffmann,&nbsp;T., Arnold,&nbsp;F., Hanke,&nbsp;M., Sellegri,&nbsp;K., Umann,&nbsp;B., Junkermann,&nbsp;W., Coe,&nbsp;H., Allan,&nbsp;J.&nbsp;D., Alfarra,&nbsp;M.&nbsp;R., Worsnop,&nbsp;D.&nbsp;R., Riekkola,&nbsp;M.-L., Hyötyläinen,&nbsp;T., and Viisanen,&nbsp;Y.: The role of VOC oxidation products in continental new particle formation, Atmos. Chem. Phys., 8, 2657–2665, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-8-2657-2008">10.5194/acp-8-2657-2008</a>, 2008. Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J. and Kulmala,&nbsp;M.: A&nbsp;model for particle formation and growth in the atmosphere with molecular resolution in size, Atmos. Chem. Phys., 3, 251–257, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-3-251-2003">10.5194/acp-3-251-2003</a>, 2003. McMurry,&nbsp;P.&nbsp;H. and Friedlander,&nbsp;S.&nbsp;K.: New particle formation in the presence of an aerosol, Atmos. Environ., 13, 1635–1651, 1979. Merikanto,&nbsp;J., Spracklen,&nbsp;D.&nbsp;V., Mann,&nbsp;G.&nbsp;W., Pickering,&nbsp;S.&nbsp;J., and Carslaw,&nbsp;K.&nbsp;S.: Impact of nucleation on global CCN, Atmos. Chem. Phys., 9, 8601–8616, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-9-8601-2009">10.5194/acp-9-8601-2009</a>, 2009. Metzger,&nbsp;A., Verheggen,&nbsp;B., Dommen,&nbsp;J., Duplissy,&nbsp;J., Prevot,&nbsp;A.&nbsp;S.&nbsp;H., Weingartner,&nbsp;E., Riipinen,&nbsp;I., Kulmala,&nbsp;M., Spracklen,&nbsp;D.&nbsp;V., Carslaw,&nbsp;K.&nbsp;S., and Baltensperger,&nbsp;U.: Evidence for the role of organics in aerosol particle formation under atmospheric conditions, P. Natl. Acad. Sci. USA, 107, 6646–6651, 2010. Nieminen,&nbsp;T., Manninen,&nbsp;H.&nbsp;E., Sihto,&nbsp;S.&nbsp;L., Yli-Juuti,&nbsp;T., Mauldin,&nbsp;R.&nbsp;L., Petaja,&nbsp;T., Riipinen,&nbsp;I., Kerminen,&nbsp;V.&nbsp;M., and Kulmala,&nbsp;M.: Connection of sulfuric acid to atmospheric nucleation in boreal forest, Environ. Sci. Technol., 43, 4715–4721, 2009. Nieminen,&nbsp;T., Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J., and Kulmala,&nbsp;M.: Sub-10 <abbr>nm</abbr> particle growth by vapor condensation – effects of vapor molecule size and particle thermal speed, Atmos. Chem. Phys., 10, 9773–9779, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-10-9773-2010">10.5194/acp-10-9773-2010</a>, 2010. O'Dowd,&nbsp;C.&nbsp;D., Aalto,&nbsp;P., Hameri,&nbsp;K., Kulmala,&nbsp;M., and Hoffmann,&nbsp;T.: Aerosol formation – atmospheric particles from organic vapours, Nature, 416, 497–498, 2002. Paasonen,&nbsp;P., Sihto,&nbsp;S.&nbsp;L., Nieminen,&nbsp;T., Vuollekoski,&nbsp;H., Riipinen,&nbsp;I., Plass-Dulmer,&nbsp;C., Berresheim,&nbsp;H., Birmili,&nbsp;W., and Kulmala,&nbsp;M.: Connection between new particle formation and sulphuric acid at Hohenpeissenberg (Germany) including the influence of organic compounds, Boreal Environ. Res., 14, 616–629, 2009. Paasonen,&nbsp;P., Nieminen,&nbsp;T., Asmi,&nbsp;E., Manninen,&nbsp;H.&nbsp;E., Petäjä,&nbsp;T., Plass-Dülmer,&nbsp;C., Flentje,&nbsp;H., Birmili,&nbsp;W., Wiedensohler,&nbsp;A., Hõrrak,&nbsp;U., Metzger,&nbsp;A., Hamed,&nbsp;A., Laaksonen,&nbsp;A., Facchini,&nbsp;M.&nbsp;C., Kerminen,&nbsp;V.-M., and Kulmala,&nbsp;M.: On the roles of sulphuric acid and low-volatility organic vapours in the initial steps of atmospheric new particle formation, Atmos. Chem. Phys., 10, 11223–11242, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-10-11223-2010">10.5194/acp-10-11223-2010</a>, 2010. Paasonen,&nbsp;P., Olenius,&nbsp;T., Kupiainen,&nbsp;O., Kurtén,&nbsp;T., Petäjä,&nbsp;T., Birmili,&nbsp;W., Hamed,&nbsp;A., Hu,&nbsp;M., Huey,&nbsp;L.&nbsp;G., Plass-Duelmer,&nbsp;C., Smith,&nbsp;J.&nbsp;N., Wiedensohler,&nbsp;A., Loukonen,&nbsp;V., McGrath,&nbsp;M.&nbsp;J., Ortega,&nbsp;I.&nbsp;K., Laaksonen,&nbsp;A., Vehkamäki,&nbsp;H., Kerminen,&nbsp;V.-M., and Kulmala,&nbsp;M.: On the formation of sulphuric acid – amine clusters in varying atmospheric conditions and its influence on atmospheric new particle formation, Atmos. Chem. Phys., 12, 9113–9133, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-12-9113-2012">10.5194/acp-12-9113-2012</a>, 2012. Riipinen,&nbsp;I., Sihto,&nbsp;S.-L., Kulmala,&nbsp;M., Arnold,&nbsp;F., Dal&nbsp;Maso,&nbsp;M., Birmili,&nbsp;W., Saarnio,&nbsp;K., Teinilä,&nbsp;K., Kerminen,&nbsp;V.-M., Laaksonen,&nbsp;A., and Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J.: Connections between atmospheric sulphuric acid and new particle formation during QUEST III–IV campaigns in Heidelberg and Hyytiälä, Atmos. Chem. Phys., 7, 1899–1914, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-7-1899-2007">10.5194/acp-7-1899-2007</a>, 2007. Riipinen, I., Pierce, J. R., Yli-Juuti, T., Nieminen, T., Häkkinen, S., Ehn, M., Junninen, H., Lehtipalo, K., Petäjä, T., Slowik, J., Chang, R., Shantz, N. C., Abbatt, J., Leaitch, W. R., Kerminen, V.-M., Worsnop, D. R., Pandis, S. N., Donahue, N. M., and Kulmala, M.: Organic condensation: a vital link connecting aerosol formation to cloud condensation nuclei (CCN) concentrations, Atmos. Chem. Phys., 11, 3865–3878, <a href="http://dx.doi.org/10.5194/acp-11-3865-2011">https://doi.org/10.5194/acp-11-3865-2011</a>, 2011. Riipinen, I., Yli-Juuti, T., Pierce, J. R., Petaja, T., Worsnop, D. R., Kulmala, M., and Donahue, N. M.: The contribution of organics to atmospheric nanoparticle growth, Nat. Geosci., 5, 453–458, 2012. Sihto,&nbsp;S.-L., Kulmala,&nbsp;M., Kerminen,&nbsp;V.-M., Dal&nbsp;Maso,&nbsp;M., Petäjä,&nbsp;T., Riipinen,&nbsp;I., Korhonen,&nbsp;H., Arnold,&nbsp;F., Janson,&nbsp;R., Boy,&nbsp;M., Laaksonen,&nbsp;A., and Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J.: Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms, Atmos. Chem. Phys., 6, 4079–4091, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-6-4079-2006">10.5194/acp-6-4079-2006</a>, 2006. Sipila,&nbsp;M., Berndt,&nbsp;T., Petaja,&nbsp;T., Brus,&nbsp;D., Vanhanen,&nbsp;J., Stratmann,&nbsp;F., Patokoski,&nbsp;J., Mauldin,&nbsp;R.&nbsp;L., Hyvarinen,&nbsp;A.&nbsp;P., Lihavainen,&nbsp;H., and Kulmala,&nbsp;M.: The role of sulfuric acid in atmospheric nucleation, Science, 327, 1243–1246, 2010. Stolzenburg, M. R., McMurry, P. H., Sakurai, H., Smith, J. N., Mauldin, R. L., Eisele, F. L., and Clement, C. F.: Growth rates of freshly nucleated atmospheric particles in Atlanta, J. Geophys. Res., 110, D22S05, <a href="http://dx.doi.org/10.1029/2005jd005935">https://doi.org/10.1029/2005jd005935</a>, 2005. Taipale,&nbsp;R., Ruuskanen,&nbsp;T.&nbsp;M., Rinne,&nbsp;J., Kajos,&nbsp;M.&nbsp;K., Hakola,&nbsp;H., Pohja,&nbsp;T., and Kulmala,&nbsp;M.: Technical Note: Quantitative long-term measurements of VOC concentrations by PTR-MS – measurement, calibration, and volume mixing ratio calculation methods, Atmos. Chem. Phys., 8, 6681–6698, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-8-6681-2008">10.5194/acp-8-6681-2008</a>, 2008. Vuollekoski,&nbsp;H., Sihto,&nbsp;S.-L., Kerminen,&nbsp;V.-M., Kulmala,&nbsp;M., and Lehtinen,&nbsp;K.&nbsp;E.&nbsp;J.: A&nbsp;numerical comparison of different methods for determining the particle formation rate, Atmos. Chem. Phys., 12, 2289–2295, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-12-2289-2012">10.5194/acp-12-2289-2012</a>, 2012. Wang,&nbsp;Z.&nbsp;B., Hu,&nbsp;M., Yue,&nbsp;D.&nbsp;L., Zheng,&nbsp;J., Zhang,&nbsp;R.&nbsp;Y., Wiedensohler,&nbsp;A., Wu,&nbsp;Z.&nbsp;J., Nieminen,&nbsp;T., and Boy,&nbsp;M.: Evaluation on the role of sulfuric acid in the mechanisms of new particle formation for Beijing case, Atmos. Chem. Phys., 11, 12663–12671, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-11-12663-2011">10.5194/acp-11-12663-2011</a>, 2011. Wehner,&nbsp;B., Wiedensohler,&nbsp;A., Tuch,&nbsp;T.&nbsp;M., Wu,&nbsp;Z.&nbsp;J., Hu,&nbsp;M., Slanina,&nbsp;J., and Kiang,&nbsp;C.&nbsp;S.: Variability of the aerosol number size distribution in Beijing, China: new particle formation, dust storms, and high continental background, Geophys. Res. Lett., 31, L22108, <a href="http://dx.doi.org/10.1029/2004gl021596">https://doi.org/10.1029/2004gl021596</a>, 2004. Wehner, B., Petäjä, T., Boy, M., Engler, C., Birmili, W., Tuch, T., Wiedensohler, A., and Kulmala, M.: The contribution of sulfuric acid and non-volatile compounds on the growth of freshly formed atmospheric aerosols, Geophys. Res. Lett., 32, L16801, <a href="http://dx.doi.org/10.1029/2005gl023827">https://doi.org/10.1029/2005gl023827</a>, 2005. Wiedensohler,&nbsp;A., Birmili,&nbsp;W., Nowak,&nbsp;A., Sonntag,&nbsp;A., Weinhold,&nbsp;K., Merkel,&nbsp;M., Wehner,&nbsp;B., Tuch,&nbsp;T., Pfeifer,&nbsp;S., Fiebig,&nbsp;M., Fjäraa,&nbsp;A.&nbsp;M., Asmi,&nbsp;E., Sellegri,&nbsp;K., Depuy,&nbsp;R., Venzac,&nbsp;H., Villani,&nbsp;P., Laj,&nbsp;P., Aalto,&nbsp;P., Ogren,&nbsp;J.&nbsp;A., Swietlicki,&nbsp;E., Williams,&nbsp;P., Roldin,&nbsp;P., Quincey,&nbsp;P., Hüglin,&nbsp;C., Fierz-Schmidhauser,&nbsp;R., Gysel,&nbsp;M., Weingartner,&nbsp;E., Riccobono,&nbsp;F., Santos,&nbsp;S., Grüning,&nbsp;C., Faloon,&nbsp;K., Beddows,&nbsp;D., Harrison,&nbsp;R., Monahan,&nbsp;C., Jennings,&nbsp;S.&nbsp;G., O'Dowd,&nbsp;C.&nbsp;D., Marinoni,&nbsp;A., Horn,&nbsp;H.-G., Keck,&nbsp;L., Jiang,&nbsp;J., Scheckman,&nbsp;J., McMurry,&nbsp;P.&nbsp;H., Deng,&nbsp;Z., Zhao,&nbsp;C.&nbsp;S., Moerman,&nbsp;M., Henzing,&nbsp;B., de&nbsp;Leeuw,&nbsp;G., Löschau,&nbsp;G., and Bastian,&nbsp;S.: Mobility particle size spectrometers: harmonization of technical standards and data structure to facilitate high quality long-term observations of atmospheric particle number size distributions, Atmos. Meas. Tech., 5, 657–685, https://doi.org/<a href="http://dx.doi.org/10.5194/amt-5-657-2012">10.5194/amt-5-657-2012</a>, 2012. Wu,&nbsp;Z.&nbsp;J., Hu,&nbsp;M., Liu,&nbsp;S., Wehner,&nbsp;B., Bauer,&nbsp;S., Ma{ß}ling,&nbsp;A., Wiedensohler,&nbsp;A., Petäjä,&nbsp;T., Dal Maso,&nbsp;M., and Kulmala,&nbsp;M.: New particle formation in Beijing, China: statistical analysis of a&nbsp;1-year data set, J. Geophys. Res., 112, D09209, <a href="http://dx.doi.org/10.1029/2006jd007406">https://doi.org/10.1029/2006jd007406</a>, 2007. Wu,&nbsp;Z.&nbsp;J., Hu,&nbsp;M., Lin,&nbsp;P., Liu,&nbsp;S., Wehner,&nbsp;B., and Wiedensohler,&nbsp;A.: Particle number size distribution in the urban atmosphere of Beijing, China, Atmos. Environ., 42, 7967–7980, 2008. Yue,&nbsp;D.&nbsp;L., Hu,&nbsp;M., Zhang,&nbsp;R.&nbsp;Y., Wang,&nbsp;Z.&nbsp;B., Zheng,&nbsp;J., Wu,&nbsp;Z.&nbsp;J., Wiedensohler,&nbsp;A., He,&nbsp;L.&nbsp;Y., Huang,&nbsp;X.&nbsp;F., and Zhu,&nbsp;T.: The roles of sulfuric acid in new particle formation and growth in the mega-city of Beijing, Atmos. Chem. Phys., 10, 4953–4960, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-10-4953-2010">10.5194/acp-10-4953-2010</a>, 2010. Yue,&nbsp;D.&nbsp;L., Hu,&nbsp;M., Zhang,&nbsp;R.&nbsp;Y., Wu,&nbsp;Z.&nbsp;J., Su,&nbsp;H., Wang,&nbsp;Z.&nbsp;B., Peng,&nbsp;J.&nbsp;F., He,&nbsp;L.&nbsp;Y., Huang,&nbsp;X.&nbsp;F., Gong,&nbsp;Y.&nbsp;G. and Wiedensohler,&nbsp;A.: Potential contribution of new particle formation to cloud condensation nuclei in Beijing, Atmos. Environ., 45, 6070–6077, 2011. Zhang,&nbsp;R., Khalizov,&nbsp;A., Wang,&nbsp;L., Hu,&nbsp;M., and Xu,&nbsp;W.: Nucleation and growth of nanoparticles in the atmosphere, Chem. Rev., 112, 1957–2011, <a href="http://dx.doi.org/10.1021/cr2001756">https://doi.org/10.1021/cr2001756</a>, 2011. Zhang,&nbsp;R.&nbsp;Y., Wang,&nbsp;L., Khalizov,&nbsp;A.&nbsp;F., Zhao,&nbsp;J., Zheng,&nbsp;J., McGraw,&nbsp;R.&nbsp;L., and Molina,&nbsp;L.&nbsp;T.: Formation of nanoparticles of blue haze enhanced by anthropogenic pollution, P. Natl. Acad. Sci. USA, 106, 17650–17654, 2009. Zheng,&nbsp;J., Hu,&nbsp;M., Zhang,&nbsp;R., Yue,&nbsp;D., Wang,&nbsp;Z., Guo,&nbsp;S., Li,&nbsp;X., Bohn,&nbsp;B., Shao,&nbsp;M., He,&nbsp;L., Huang,&nbsp;X., Wiedensohler,&nbsp;A., and Zhu,&nbsp;T.: Measurements of gaseous H<sub>2</sub>SO<sub>4</sub> by AP-ID-CIMS during CAREBeijing 2008 Campaign, Atmos. Chem. Phys., 11, 7755–7765, https://doi.org/<a href="http://dx.doi.org/10.5194/acp-11-7755-2011">10.5194/acp-11-7755-2011</a>, 2011.