title: Surface tension of mixed inorganic and dicarboxylic acid aqueous solutions at 298.15 K and their importance for cloud activation predictions.
abstract: The following study extends previous work on modelling multicomponent surface tensions and the impact they have on aerosol and climate modelling. Mixed dicarboxylic acid and ammonium sulfate solution surface tensions have been measured experimentally and were modelled using an additive, a semi-empirical and two thermodynamic methods. A thermodynamic method with parameters fitted to binary solution data reproduced experimental results most closely with average absolute deviation from the experimental data over all measurements of 2.6%, compared with 7.7% for the additive, 8.1% for the semi-empirical and 7.3% for the other thermodynamic method. The choice of surface tension modelling method can lead to differences of up to 50% in the critical saturation ratios of aerosol particles. When applied to a trimodal aerosol distribution this leads to a difference in dry diameter for activation of 30 to 40 nm. This is greater than the difference induced by changing inorganic to organic mass ratios (>10 nm).
authors.affiliation: Centre for Atmospheric Science, School of Earth Atmospheric and Environmental Science, Simon Building, Oxford Road, University of Manchester, Manchester, UK M13 9PL. alastair.booth@manchester.ac.uk
authors.forename: Alastair Murray
authors.initials: AM
authors.lastname: Booth
authors.forename: David Owen
authors.initials: DO
authors.lastname: Topping
authors.forename: Gordon
authors.initials: G
authors.lastname: McFiggans
authors.forename: Carl John
authors.initials: CJ
authors.lastname: Percival
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry*; D045424:Complex Mixtures / Q000737:chemistry; D003998:Dicarboxylic Acids / Q000737:chemistry*; D005544:Forecasting; D005740:Gases / Q000737:chemistry / Q000302:isolation & purification; D007287:Inorganic Chemicals / Q000737:chemistry*; D008956:Models, Chemical; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D012996:Solutions; D013500:Surface Tension; D013696:Temperature; D014867:Water / Q000737:chemistry*; D014887:Weather
chemical_list: D000336:Aerosols; D045424:Complex Mixtures; D003998:Dicarboxylic Acids; D005740:Gases; D007287:Inorganic Chemicals; D052638:Particulate Matter; D012996:Solutions; D014867:Water