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CCN predictions and and the role of organics. Development of a simple model predicting Cloud Condensatio n Nuclei concentrations, CCN Applying the model on data from CLAIRE 2001 Hygroscopic measurements on some organics (laboratory data). Jenny Rissler, Aerosolgroup, Lund University.
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CCN predictions and and the role of organics Development of a simple model predicting Cloud Condensation Nuclei concentrations, CCN Applying the model on data from CLAIRE 2001 Hygroscopic measurements on some organics (laboratory data) Jenny Rissler, Aerosolgroup, Lund University
Overview of the model Overwiew of the model H-TDMA Hygroscopic Tandem Differential Mobility Analyzer e Soluble volume fraction Ni Number of soluble ions as a function of particle size Sc Critical super- saturation as function of particle size dact Activation (dry) diameter for a specific supersaturation DMPS Differential Mobility Particle Size Inverted Size distribution CCN
Köhler Curve Classical Köhler theory: Critical saturation ratio
Calculating epsilon The soluble volume fraction (epsilon) is calculated according to: Equation 1 The growth factor for the model salt is calculated from Tang’s salt data (molality as a function of water activity, and density as a function of mole fraction of the solution).
Calculations Classical Köhler theory: Critical saturation ratio or: Where Sc is the saturation ratio and and Finding the critical super saturation through derivation gives: Where is the supersaturation Sc-1=sc or:
CLAIRE 2001 Some results
CLAIRE 2001 Some results (cont.)
Some results (cont.) CLAIRE 2001
Some results (cont.) CLAIRE 2001
Organic Lab Measurements Hygroscopic growth at subsaturation (H-TDMA) Jenny Rissler, Jingchuan Zhou, Erik Swietlicki Div. of Nuclear Physics, Lund University, Sweden Activation at supersaturation (CCNC) Birgitta Svenningsson, Merete Bilde Dept. of Chemistry, Copenhagen University, Denmark (not official SMOCC partners)
Compounds • Fulvic acid • Succinic acid • Maleic acid • Levoglucosan Pure compounds and mixtures representative to the composition in certain aerosol, such as particles from aged biomass burning and marine aerosol.
Svenningsson et al., Copenhagen Org meas CCN
Lund (+ Copenhagen) Preliminary results Organic measurements 2.4 MIXBIO MIXBIO fromCCNC 2.2 MIXORG MIXPO 2 MIX 1 MIXSEA DEL 1.8 MIXSEA Growth factor Calculated Gf from Gf of pure compounds 1.6 1.4 1.2 1 0 10 20 30 40 50 60 70 80 90 100 RH (%)
Lund (+ Copenhagen) Preliminary results