Journal article

Evaluation of a global aerosol microphysics model against size-resolved particle statistics in the marine atmosphere

Spracklen D, Pringle K, Carslaw K, Mann G, Manktelow P, Heintzenberg J ...see all

Atmos. Chem. Phys. Atmospheric Chemistry and Physics, vol. 7 (2007) pp. 2073-2090

  • 44


    Mendeley users who have this article in their library.
  • 27


    Citations of this article.
Sign in to save reference


A statistical synthesis of marine aerosol measure-ments from experiments in four different oceans is used to evaluate a global aerosol microphysics model (GLOMAP). We compare the model against observed size resolved parti-cle concentrations, probability distributions, and the tempo-ral persistence of different size particles. We attempt to ex-plain the observed sub-micrometre size distributions in terms of sulfate and sea spray and quantify the possible contribu-tions of anthropogenic sulfate and carbonaceous material to the number and mass distribution. The model predicts a bi-modal size distribution that agrees well with observations as a grand average over all regions, but there are large regional differences. Notably, observed Aitken mode number concen-trations are more than a factor 10 higher than in the model for the N Atlantic but a factor 7 lower than the model in the NW Pacific. We also find that modelled Aitken mode and accumulation mode geometric mean diameters are gen-erally smaller in the model by 10–30%. Comparison with ob-served free tropospheric Aitken mode distributions suggests that the model underpredicts growth of these particles dur-ing descent to the marine boundary layer (MBL). Recent ob-servations of a substantial organic component of free tropo-spheric aerosol could explain this discrepancy. We find that anthropogenic continental material makes a substantial con-tribution to N Atlantic MBL aerosol, with typically 60–90% of sulfate across the particle size range coming from anthro-pogenic sources, even if we analyse air that has spent an aver-age of >120 h away from land. However, anthropogenic pri-mary black carbon and organic carbon particles (at the emis-sion size and quantity assumed here) do not explain the large discrepancies in Aitken mode number. Several explanations for the discrepancy are suggested. The lack of lower atmo-spheric particle formation in the model may explain low N Atlantic particle concentrations. However, the observed and Correspondence to: D. V. Spracklen ( modelled particle persistence at Cape Grim in the Southern Ocean, does not reveal a diurnal cycle consistent with a pho-tochemically driven local particle source. We also show that a physically based cloud drop activation scheme better ex-plains the observed change in accumulation mode geometric mean diameter with particle number.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • D V Spracklen

  • K J Pringle

  • K S Carslaw

  • G W Mann

  • P Manktelow

  • J Heintzenberg

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free