HR: 11:20h
AN: A42B-05    [Abstracts]
TI: Size-Resolved CCN Spectra of Marine, Continental, and Pyrogenic Aerosols - A Comparison
AU: * Frank, G P
EM: gfrank@mpch-mainz.mpg.de
AF: Biogeochemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainy, D-55020 Germany
AU: Dusek, U
A42B-05 AF: Biogeochemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainy, D-55020 Germany
AU: Hildebrandt, L
A42B-05 AF: California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 United States
AU: Allen, J D
A42B-05 AF: Atmospheric Research Group, The University of Manchester, P.O. Box 88 , Manchester, M60 1QD United Kingdom
AU: Drewnick, F
A42B-05 AF: Particle Chemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AU: Hings, S
A42B-05 AF: Particle Chemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AU: Hoffer, A
A42B-05 AF: Biogeochemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainy, D-55020 Germany
AU: Hoffer, A
A42B-05 AF: University of Veszprem, P.O. Box 158, Veszprem, H-8201 Hungary
AU: Iinuma, Y
A42B-05 AF: Leibniz Institute for Tropospheric Research, Permoserstr. 15, Leipzig, D-04318 Germany
AU: Schneider, J
A42B-05 AF: Particle Chemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AU: Walter, S
A42B-05 AF: Particle Chemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AU: Borrmann, S
A42B-05 AF: Particle Chemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AU: Coe, H
A42B-05 AF: Atmospheric Research Group, The University of Manchester, P.O. Box 88 , Manchester, M60 1QD United Kingdom
AU: Herrmann, H
A42B-05 AF: Leibniz Institute for Tropospheric Research, Permoserstr. 15, Leipzig, D-04318 Germany
AU: Andreae, M O
A42B-05 AF: Biogeochemistry Department, Max Planck Institute for Chemistry, P.O. Box 3060, Mainy, D-55020 Germany
AB: The supersaturation (S) at which an aerosol particle is activated to grow into a cloud droplet depends on the particle size and chemical composition. Currently, there are still many open questions how the complex chemistry of ambient particles influences their cloud nucleating properties. Size resolved measurements of cloud condensation nuclei (CCN) help to separate the effect of particle size from the effect of chemical composition and give new insights into the activation behavior of ambient aerosol particles. Over the past years we measured size resolved CCN spectra during four field and one laboratory experiment, focusing on different aerosol types: Fresh biomass burning aerosol (EFEU), aged continental aerosol (FACE-2004, FACE-2005, MOHp), and marine aerosol (RICO-PRACS). We will compare and contrast the CCN spectra, measured for these aerosol types, and relate the findings to particle chemical composition. A differential mobility analyzer was used to select a fraction of the aerosol particles within a narrow electrical mobility range. These nearly monodisperse particles were passed on to a CCN counter. A condensation particle counter, parallel to the CCN counter, determined the total particle concentration (CN). This information can be used to derive the CCN activation efficiency, defined as the number of CCN divided by the number of CN, at each particle diameter and S. At S=0.4%, marine aerosols are activated at same diameter as pure ammonium sulfate, 50 nm. Continental and pyrogenic aerosol particles require increasingly larger particle diameters for activation, 75 respective 125 nm, indicating the presence of insoluble or poorly soluble material in the particles. In addition the activation curves become less steep, indicating heterogeneities in particle chemical composition and/or shape.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005