Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 9 3 2009 10.5194/acp-9-937-2009 http://www.atmos-chem-phys.net/9/937/2009/ http://www.atmos-chem-phys.net/9/937/2009/acp-9-937-2009.html http://www.atmos-chem-phys.net/9/937/2009/acp-9-937-2009.pdf 937 944 2009-02-06 Airborne measurements of nucleation mode particles II: boreal forest nucleation events C. D. O'Dowd colin.odowd@nuigalway.ie Y. J. Yoon W. Junkermann P. Aalto M. Kulmala H. Lihavainen Y. Viisanen School of Physics {&} Centre for Climate and Air Pollution Studies, Environmental Change Institute, National University of Ireland, Galway, University Road, Galway, Ireland Korea Polar Research Institute, KORDI, 7-50, Songdo-dong, Incheon 406-840, Korea Fraunhofer Institute for Atmospheric Environmental Research, Kreuzeckbahnstr. 19, \newline 82467 Garmisch-Partenkirchen, Germany Department of Physical Sciences, P.O. Box 64 (Gustaf Hällströmin katu 2) PL 64, 00014 University of Helsinki, Finland Finnish Meteorological Institute, Erik Palménin aukio, P.O. Box 503 00101, Helsinki Airborne measurements of nucleation mode aerosol concentrations during nucleation events over the boreal forest of southern Finland are reported. Three case studies are analyzed in an attempt to characterise the spatial scales over which these events occur and to identify the source region for particle production. For the cases presented, there is no evidence of nucleation mode particles in the Free Troposphere. Nucleation mode particles are first detected in the surface layer as the nocturnal inversion breaks up and develops into the current-day's new boundary layer. In terms of spatial variability, significant variability in the concentration of nucleation mode particles was observed and was attributed to changes in the topography which comprised a mix of forest canopy and frozen lakes. Measurements over the Gulf of Bothnia indicated no nucleation mode over the sea and confirm that the scale of the events is associated with the boreal forest scale and that the new particles are produced directly above the forest canopy. Charlson, R. J., Lovelock, J. E., Andreae, M. O., and Warren, S. G.: Oceanic Phytoplankton, Atmospheric Sulfur, Cloud Albedo And Climate, Nature, 326, 655–661, 1987. Hansson, H. C, and O'Dowd, C. D. (eds.): Common Issues: Air Quality & Climate – Research & Policy, ACCENT Publication 06.4, 2006 ISBN:0-9553862-0-9, 2006. Intergovernmental Panel on Climate Change (IPCC), Climate Change 2007: The physical scientific basis, edited by: Solomon, S., Quin, D. Manning, U. et al., Common Issues Cambridge Univ. Press, New York, USA, 2007. Junkermann, W.: The actinic UV-radiation budget during the ESCOMPTE campaign 2001: Results of airborne measurements with the microlight research aircraft D-MIFU, Atmos. Res., 74, 461–475, 2005. Kulmala, M., Hämeri, K., Aalto, P. P., Makela, L. M., Pirjola, L., Nilsson, E. D., Buzorius, G., Rannik, U., Dal Maso, M., Seidl, W., Hoffmann, T., Janson, R., Hansson, H.-C., Viisanen, Y., Laaksonen, A., and O'Dowd, C. D.: Overview of the international project on biogenic aerosol formation in the boreal forest (BIOFOR), Tellus B, 324–343, 2001. Kulmala, M., Laakso, L., Lehtinen, K. E. J., Riipinen, I., Dal Maso, M., Anttila, T., Kerminen, V.-M., Horrak, U., Vana, M., and Tammet, H.: Initial steps of aerosol growth, Atmos. Chem. Phys., 4, 2553–2560, 2004. Laaksonen, A., Kulmala, M., O'Dowd, C. D., Viisanen, Y., Nilsson, D., Facchini, M. C., Hoffmann, T., Arnold, F., Schell, B., and Junkermann, W.: Preliminary results from the Quest project (quantification of aerosol nucleation in the European boundary layer). In: Abstracts of the European Aerosol Conference 2003, Madrid, Spain, 31 August–5 September 2003, S1337–S1338, 2, 2003. Nilsson, E. D., Rannik, U., Buzorius, G., and O'Dowd, C. D.: Effects of continental boundary layer evolution, convection, turbulence and entrainment on aerosol formation, Tellus B, 53, 441–461, 2001. O'Dowd, C. D., Aalto, P., Hämeri, K., Kulmala, M., and Hoffmann, T.: Atmospheric particles from organic Vapours, Nature, 416, 497–498, 2002. O'Dowd, C. D., Facchini, M. C., Cavalli, F., Ceburnis, D., Mircea, M., Decesari, S., Fuzzi, S., Yoon, Y. J., and Putaud, J. P.: Biogenically-driven organic contribution to marine aerosol, Nature, 431, 676–680, doi:10.1038/nature02959, 2004. O'Dowd, C. D, Yoon, Y. J., Junkermann, W., Aalto, P. P., and Lihavainen, H.: Airborne Measurements of Nucleation Mode Particles I: Coastal Atlantic Nucleation Events, Atmos. Chem. Phys., 7, 1491–1501, 2007. Raes, F.: Entrainment of free tropospheric aerosols as a regulating mechanism for cloud condensation nuclei in the remote marine boundary layer, J. Geophys. Res., 100, 2893–2903, 1995. Stratmann, F., Siebert, H., Spindler, G., Wehner, B., Althausen, D., Heintzenberg, J., Hellmuth, O., Rinke, R., Schmieder U., Seidel, C., Tuch, T., Uhrner, U., Wiedensohler, A. Wandinger, U., Wendisch, M., Schell, D., and Stohl, A.: New-particle formation events in a continental boundary layer: First results from the SATURN experiment, 3, 1445–1459, Atmos. Chem. Phys., 2003. Tunved, P., Hansson, H.-C., Kerminen, V.-M., Ström, J., Dal Maso, M., Lihavainen, H., Viisanen, Y., Aalto, P. P., Komppula, M., and Kulmala, M.: High natural aerosol loading over boreal forests, Science, 14(312), 261–263, doi:10.1126/science.1123052, 2006.