ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-3743-2010 Factors influencing the contribution of ion-induced nucleation in a boreal forest, Finland Gagné S. 1 Nieminen T. 1 Kurtén T. 1 2 Manninen H. E. 1 Petäjä T. 1 Laakso L. 1 3 Kerminen V.-M. 1 4 Boy M. 1 Kulmala M. 1 5 Department of Physics, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark School of Physical and Chemical Sciences, North-West University, Private Bag x6001, Potchefstroom 2520, South Africa Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland Department of Applied Environmental Science, Stockholm University, 10691 Stockholm, Sweden 21 04 2010 10 8 3743 3757 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/10/3743/2010/acp-10-3743-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/3743/2010/acp-10-3743-2010.pdf

We present the longest series of measurements so far (2 years and 7 months) made with an Ion-DMPS at the SMEAR II measurement station in Hyytiälä, Southern Finland. We show that the classification into overcharged (implying some participation of ion-induced nucleation) and undercharged (implying no or very little participation of ion-induced nucleation) days, based on Ion-DMPS measurements, agrees with the fraction of ion-induced nucleation based on NAIS measurements. Those classes are based on the ratio of ambient charged particle to steady-state charged particle concentration, known as the charging state. We analyzed the influence of different parameters on the contribution of ion-induced nucleation to the total particle formation rate. We found that the fraction of ion-induced nucleation is typically higher on warmer, drier and sunnier days compared to colder days with less solar radiation and a higher relative humidity. Also, we observed that bigger concentrations of new particles were produced on days with a smaller fraction of ion-induced nucleation. Moreover, sulfuric acid saturation ratios were smaller for days with a bigger fraction of ion-induced nucleation. Finally, we propose explanations on how these different parameters could influence neutral and ion-induced nucleation, and show that the different mechanisms seem to take place at the same time during an event. For example, we propose that these observed differences could be due to high temperature and low vapors' saturation ratios (water and sulfuric acid) increasing the height of the energy barrier a particle has to reach before it can grow and thus limiting neutral nucleation.

 References Aalto, P., Hämeri, K., Becker, E., Weber, R., Salm, J., Mäkelä, J. M., Hoell, C., O'Dowd, C. D., Karlsson, H., Hansson, H.-C., Väkevä, M., Koponen, I. K., Buzorius, G., and Kulmala, M.: Physical characterization of aerosol particles during nucleation events, Tellus, 53B, 344–358, 2001. Andreae, M. O. and Rosenfeld, D.: Aerosol-cloud-precipitation interactions. Part 1. The nature and sources of cloud-active aerosols, Earth-Science Reviews, 89, 13–41, 2008. Birmili, W., Berresheim, H., Plass-Dülmer, C., Elste, T., Gilge, S., Wiedensohler, A., and Uhrner, U.: The Hohenpeissenberg aerosol formation experiment (HAFEX): a long-term study including size-resolved aerosol, H<sub>2</sub>SO<sub>4</sub>, OH, and monoterpenes measurements, Atmos. Chem. Phys., 3, 361–376, 2003. Boy, M. and Kulmala, M.: Nucleation events in the continental boundary layer: Influence of physical and meteorological parameters, Atmos. Chem. Phys., 2, 1–16, 2002. Boy, M., Rannik, Ü., Lehtinen, K. E. J., Tarvainen, V., Hakola, H., and Kulmala, M.: Nucleation events in the continental PBL – long term statistical analyses of aerosol relevant characteristics, J. Geophys. Res., 108(D21), 4667, doi:10.1029/2003JD003838, 2003. Boy, M., Kulmala, M., Ruuskanen, T. M., Pihlatie, M., Reissell, A., Aalto, P. P., Keronen, P., Dal Maso, M., Hellen, H., Hakola, H., Jansson, R., Hanke, M., and Arnold, F.: Sulphuric acid closure and contribution to nucleation mode particle growth, Atmos. Chem. Phys., 5, 863–878, 2005. Boy, M., Hellmuth, O., Korhonen, H., Nilsson, E. D., ReVelle, D., Turnipseed, A., Arnold, F., and Kulmala, M.: MALTE – model to predict new aerosol formation in the lower troposphere, Atmos. Chem. Phys., 6, 4499–4517, 2006. Boy, M., Kazil, J., Lovejoy, E. R., Guenther, A., and Kulmala, M.: Relevance of ion-induced nucleation of sulfuric acid and water in the lower troposphere over the boreal forest at northern latitudes, Atmos. Res., 9, 151–158, 2008. Dal Maso, M., Kulmala, M., Riipinen, I., Wagner, R., Hussein, T., Aalto, P. P., and Lehtinen, K. E. J.: Formation and growth of fresh atmospheric aerosols: Eight years of aerosol size distribution data from SMEAR II, Hyytiälä, Finland. Boreal Environ. Res., 10(5), 323–336, 2005. Eisele, F., Lovejoy, E. R., Kosciuch, E., Moore, K. F., Mauldin III, R. L., Smith, J. N., McMurry, P. H., and Iida, K.: Negative atmospheric ions and their potential role in ion-induced nucleation, J. Geophys. Res. 111, D04305/04301–D04305/04311, doi:10.1029/2005JD006568, 2006. Gagné, S., Laakso, L., Petäjä, T., Kerminen, V.-M., and Kulmala, M.: Analysis of one year of Ion-DMPS data from the SMEAR II station, Finland, Tellus, 60B, 318–329, 2008. Hari, P. and Kulmala, M.: Station for measuring ecosystem-atmosphere relations (SMEAR II), Boreal Env. Res., 10(5), 315–322, 2005. Hatakka, J., Paatero, J., Viisanen, Y., and Mattsson, R.: Variations of external radiation due to meteorological and hydrological factors in central Finland, Radiochemistry, 40(6), 534–538, 1998. Hirsikko, A., Laakso, L., Hõrrak, U., Aalto, P. P., Kerminen, V.-M., and Kulmala, M.: Annual and size dependent variation of growth rates and ion concentrations in boreal forest, Boreal Env. Res., 10, 357–369, 2005. Hoppel, W. A.: Determination of the aerosol size distribution from the mobility distribution of the charged fraction of aerosols, J. Aerosol Sci., 9, 41–54, 1978. Iida, K., Stolzenburg, M., McMurry, P. H., Dunn, M., Smith, J., Eisele, F., and Keady, P.: Contribution of ion-induced nucleation to new particle formation: Methodology and its application to atmospheric observations in Boulder, Colorado, J. Geophys. Res., 111, D23201, doi:10.1029/2006JD007167, 2006. Iida, K., Stolzenburg, M. R., McMurry, P. H., and Smith, J. N.: Estimating nanoparticle growth rates from size-dependent charged fractions: Analysis of new particle formation events in Mexico City, J. Geophys. Res., 113, D05207, doi:10.1029/2007JD009260, 2008. Kerminen, V.-M., Anttila, T., Petäjä, T., Laakso, L., Gagné, S., Lehtinen, K. E. J., and Kulmala, M.: Charging state of the atmospheric nucleation mode: Implications for separating neutral and ion-induced nucleation, J. Geophys. Res., 112, D21205, doi:10.1029/2007JD008649, 2007. Kuang, C., McMurry, P. H., McCormick, A. V., and Eisele, F. L.: Dependence of nucleation rates on sulfuric acid vapor concentration in diverse atmospheric locations, J. Geophys. Res., 113, D10209, doi:10.1029/2007JD009253, 2008. Kulmala, M., Dal Maso, M., Mäkelä, J., Pirjola, L., Väkevä, M., Aalto, P., Miikkulainen, P., Hämeri, K., and O'Dowd, C. D.: On the formation, growth and composition of nucleation mode particles, Tellus 53B, 479–490, 2001. Kulmala, M.: How particles nucleate and grow, Science, 302, 1000–1001, 2003. Kulmala, M., Vehkamäki, H., Petäjä, T., Dal Maso, M., Lauri, A., Kerminen, V.-M., Birmili, W., and McMurry, P. H.: Formation and growth rates of ultrafine atmospheric particles: a review of observations, J. Aerosol Sci., 35, 143–176, 2004. Kulmala, M., Lehtinen, K. E. J., and Laaksonen, A.: Cluster activation theory as an explanation of the linear dependence between formation rate of 3 nm particles and sulphuric acid concentration, Atmos. Chem. Phys., 6, 787–793, 2006. Kulmala, M., Riipinen, I., Sipilä, M., Manninen, H. E., Petäjä, T. Junninen, H., Dal Maso, M., Mordas, G., Mirme, A., Vana, M., Hirsikko, A., Laakso, L., Harrison, R. M., Hanson, I., Leung, C., Lehtinen, K. E. J., Kerminen, V.-M.: Toward direct measurement of atmospheric nucleation, Science, 318, 89–92, 2007a. Kulmala, M., Mordas, G., Petäjä, T., Grönholm, T., Aalto, P. P., Vehkamäki, H., Hienola, A. I., Herrmann, E., Sipilä, M., Riipinen, I., Manninen, H. E., Hämeri, K., Stratmann, F., Bilde, M., Winkler, P. M., Birmili, W. and Wagner, P. E.: The condensation particle counter battery (CPCB): A new tool to investigate the activation properties of nanoparticles, J. Aerosol Sci., 38, 289–304, 2007b. Kulmala, M. and Kerminen, V.-M.: On the formation and growth of atmospheric nanoparticles, Atmos. Res., 90, 132–150, 2008. Kurtén, T., Noppel, M., Vehkamäki, H., Salonen, M., and Kulmala, M.: Quantum chemical studies of hydrate formation of H<sub>2</sub>SO<sub>4</sub> and HSO$_4^-$, Boreal Environ. Res., 12, 421–430, 2007. Kurtén, T., Loukonen, V., Vehkamäki, H., and Kulmala, M.: Amines are likely to enhance neutral and ion-induced sulfuric acid-water nucleation in the atmosphere more effectively than ammonia, Atmos. Chem. Phys., 8, 4095–4103, 2008. Kurtén, T., Ortega, I. K., and Vehkamäki, H.: The sign preference in sulfuric acid nucleation, Journal of Molecular Structure: THEOCHEM, 901, 169–173, 2009. Laakso, L., Petäjä, T., Lehtinen, K. E. J., Kulmala, M., Paatero, J., Hõrrak, U., Tammet, H., and Joutsensaari, J.: Ion production rate in a boreal forest based on ion, particle and radiation measurements, Atmos. Chem. Phys., 4, 1933–1943, 2004. Laakso, L., Gagné, S., Petäjä, T., Hirsikko, A., Aalto, P. P., Kulmala, M., and Kerminen, V.-M.: Detecting charging state of ultra-fine particles: instrumental development and ambient measurements, Atmos. Chem. Phys., 7, 1333–1345, 2007. Laakso, L., Gronholm, T., Kulmala, L., Haapanala, S., Hirsikko, A., Lovejoy, ER., Kazil, J, Kurten, T., Boy, M., Nilsson, E. D., Sogachev, A., Riipinen, I., Stratmann, F., and Kulmala, M.: Hot-air balloon as a platform for boundary layer profile measurements during particle formation, Boreal Environ. Res., 12(3), 279–294, 2007b. Lohmann, U. and Feichter, J.: Global indirect aerosol effects: a review, Atmos. Chem. Phys., 5, 715–737, 2005. Lovejoy, E. R., Curtius, J., and Froyd, K. D.: Atmospheric ion-induced nucleation of sulfuric acid and water, J. Geophys. Res., 109, D08204, doi:10.1029/2003JD004460, 2004. Mäkelä, J. M., Riihelä, M., Ukkonen, A., Jokinen, V., and Keskinen, J.: Comparison of mobility equivalent diameter with Kelvin-Thomson diameter using ion mobility data, J. Chem. Phys., 105, 1562–1571, 1996. Mäkelä, J. M., Salm, J., Smirnov, V. V., Koponen, I., Paatero, J., and Pronin, A. A.: Electrical charging state of fine and ultrafine particles in boreal forest air, J. Aerosol Sci., 32, 149–150, 2003. Manninen, H. E., Nieminen, T., Riipinen, I., Yli-Juuti, T., Gagné, S., Asmi, E., Aalto, P. P., Petäjä, T., Kerminen, V.-M., and Kulmala, M.: Charged and total particle formation and growth rates during EUCAARI 2007 campaign in Hyytiälä, Atmos. Chem. Phys., 9, 4077–4089, 2009. Manninen, H. E., Petäjä, T., Asmi, E., Riipinen, I., Nieminen, T., Mikkilä, J., Hõrrak, U., Mirme, A., Mirme, S., Laakso, L., Kerminen, V.-M., and Kulmala, M.: Long-term field measurements of charged and neutral clusters using Neutral cluster and Air Ion Spectrometer (NAIS), Boreal Env. Res, 14, 591–605, 2009b. Merikanto, J., Spracklen, D. V., Mann, G. W., Pickering, S. J., and Carslaw, K. S.: Impact of nucleation on global CCN, Atmos. Chem. Phys., 9, 8601–8616, 2009. Mertes, S., Schröder, F., and Wiedensohler, A.: The particle detection efficiency curve of the TSI-3010 CPC as a function of temperature difference between saturator and condenser, Aerosol Sci. Technol., 23, 257–261, 1995. Mirme, A., Tamm, E., Mordas, G., Vana, M., Uin, J., Mirme, S., Bernotas, T., Laakso, L., Hirsikko, A., and Kulmala, M.: A widerange multi-channel Air Ion Spectrometer, Boreal Env. Res., 12, 247–264, 2007. Mirme, S., Mirme, A., Minikin, A., Petzold, A., Hõrrak, U., Kerminen, V.-M., and Kulmala, M.: Atmospheric sub-3 nm particles at high altitudes, Atmos. Chem. Phys., 10, 437–451, 2010. Myhre, G., Berglen, T. F., Johnsrud, M., Hoyle, C. R., Berntsen, T. K., Christopher, S. A., Fahey, D. W., Isaksen, I. S. A., Jones, T. A., Kahn, R. A., Loeb, N., Quinn, P., Remer, L., Schwarz, J. P., and Yttri, K. E.: Modelled radiative forcing of the direct aerosol effect with multi-observation evaluation, Atmos. Chem. Phys., 9, 1365–1392, 2009. Nieminen, T., Manninen, H. E., Sihto, S.-L., Yli-Juuti, T., Mauldin III, R. L., Petäjä, T., Riipinen, I., Kerminen, V.-M., and Kulmala, M.: Connection of Sulfuric Acid to Atmospheric Nucleation in Boreal Forest, Environ. Sci. Technol., 43, 4715–4721, 2009. Nilsson, E. D., Rannik, U., Kulmala, M., Buzorius, G., and O'Dowd, C. D.: Effect of the continental boundary layer evolution, convection, turbulence and entrainment on aerosol formation, Tellus, 53B, 441–461, 2001. Paatero, J., Hatakka, J., and Viisanen, Y.: Concurrent Measurements of Airborne Radon-222, Lead-210 and Beryllium-7 at the Pallas-Sodankylä GAW Station, Northern Finland. Tech. rep., Finnish Meteorological Institute, 1998. Riipinen, I., Sihto, S.-L., Kulmala, M., Arnold, F., Dal Maso, M., Birmili, W., Saarnio, K., Teinilä, K., Kerminen, V.-M., Laaksonen, A., and Lehtinen, K. E. 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, 2007. Sogachev, A. and Panferov, O.: Modification of two-equation models to account for plant drag, Bound. Lay. Meteorol., 121, 229–266, 2006. Stanier, C. O., Khlystov, A. Y., and Pandis, S. N.: Nucleation events during the Pittsburgh Air Quality Study: Description and relation to key meteorological, gas phase, and aerosol parameters, Aerosol Sci. Technol., 38, 253–264, 2004. Stolzenburg, M. R. and McMurry, P. H.: An ultrafine aerosol condensation nucleus counter, Aerosol Sci. Technol., 14, 48–65, 1991. Spracklen, D. V., Carslaw, K. S., Kulmala, M., Kerminen, V.-M., Sihto, S.-L., Riipinen, I., Merikanto, J., Mann, G. W., Chipperfield, M. P., Wiedensohler, A., Birmili, W., and Lihavainen, H.: Contribution of particle formation to global cloud condensation nuclei concentrations, Geophys. Res. Lett., 35, L06808, doi:10.1029/2007GL033038, 2008. Stevens, B. and Feingold, G.: Untangling aerosol effects on clouds and precipitation in a buffered system, Nature, 461, 607–613, doi:10.1038/nature08281, 2009. Tammet, H.: Size and mobility of nanometer particles, clusters and ions, J. Aerosol Sci., 26, 459–475., 1995. Tammet, H.: Reduction of air ion mobility to standard conditions, J. Geophys. Res.-Atmos., 103, 13933–13937, 1998. Tammet, H.: Continuous scanning of the mobility and size distribution of charged clusters and particles in atmospheric air and the balanced scanning mobility analyzer BSMA, Atmos. Res., 82, 523–535, 2006. Twomey, S.: Aerosols, clouds and radiation, Atmos. Environ., 25A, 2435–2442, 1991. Vana, M., Tamm, E., Hõrrak, U., Mirme, A., Tammet, H., Laakso, L., Aalto, P., and Kulmala, M.: Charging state of atmospheric nanoparticles during the nucleation burst events, Atmos. Res., 82, 536–546, 2006. Vehkamäki, H., Dal Maso, M., Hussein, T., Flanagan, R., Hyvärinen, A., Lauros, J., Merikanto, P., Mönkkönen, M., Pihlatie, K., Salminen, K., Sogacheva, L., Thum, T., Ruuskanen, T. M., Keronen, P., Aalto, P. P., Hari, P., Lehtinen, K. E. J., Rannik, Ü, and Kulmala, M.: Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998–2002, Atmos. Chem. Phys., 4, 2015–2023, 2004. Vesala, T., Haataja, J., Aalto, P., Altimir, N., Buzorius, G., Garam, E., Hämeri, K., Ilvesniemi, H., Jokinen, V., Keronen, P., Lahti, T., Markkanen, T., Mäkelä, J., Nikinmaa, E., Palmroth, S., Palva, L., Pohja, T., Pumpanen, J., Rannik, Ü., Siivola, E., Ylitalo, H., Hari, P., and Kulmala, M.: Long-term field measurements of atmosphere-surface interactions in boreal forest combining forest ecology, micrometeorology, aerosol physics and atmospheric chemistry, Trends in Heat, Mass and Momentum Transfer, 4, 17–35, 1998. Weber, R. J., Marti, J. J., McMurry, P. H., Eisele, F. L., Tanner, D. J. and Jefferson, A.: Measured atmospheric new particle formation rates: implications for nucleation mechanisms, Chem. Eng. Commun., 151, 53–64, 1996. Winkler, P. M., Steiner, G., Virtala, A., Vehkamäki, H., Noppel, M., Lehtinen, K. E. J., Reischl, G. P.,Wagner, P. E., and Kulmala, M.: Heterogeneous Nucleation Experiments Bridging the Scale from Molecular Ion Clusters to Nanoparticles, Science, 319, 1374, doi:10.1126/science. 1149034, 2008. Winklmayr, W., Reischl, G., Lindner, A., and Berner, A.: A new electromobility spectrometer for the measurement of aerosol size distributions in the size range from 1 to 1000 nm, J. Aerosol Sci., 22, 289–296, 1991. Yu, F. and Turco, R.: From molecular clusters to nanoparticles: role of ambient ionization in tropospheric aerosol formation, J. Geophys. Res., 106, 4797–4817, 2001. Yu, F. and Turco, R.: Case studies of particle formation events observed in boreal forests: implications for nucleation mechanisms, Atmos. Chem. Phys., 8, 6085–6102, 2008.