Sensitivities of the absorptive partitioning model of secondary organic aerosol formation to the inclusion of water M. Barley1, D. O. Topping1,2, M. E. Jenkin3, and G. McFiggans1 1Centre for Atmospheric Sciences, School of Earth, Atmospheric & Environmental Sciences, University of Manchester, Manchester, M13 9PL, UK 2National Centre for Atmospheric Sciences, University of Manchester, Manchester, M13 9PL, UK 3Atmospheric Chemistry Services, Yelverton, Devon, PL20 6EN, UK
Abstract. The predicted distribution of semi-volatile organic components between the
gaseous and condensed phase as a function of ambient relative humidity and
the specific form of the partitioning model used has been investigated. A
mole fraction based model, modified so as not to use molar mass in the
calculation, was found to predict identical RH dependence of component
partitioning to that predicted by the conventional mass-based partitioning
model which uses a molar mass averaged according to the number of moles in
the condensed phase. A recently reported third version of the partitioning
model using individual component molar masses was shown to give significantly
different results to the other two models. Further sensitivities to an
assumed pre-existing particulate loading and to parameterised organic
component non-ideality are explored and shown to contribute significantly to
the variation in predicted secondary organic particulate loading.
Citation: Barley, M., Topping, D. O., Jenkin, M. E., and McFiggans, G.: Sensitivities of the absorptive partitioning model of secondary organic aerosol formation to the inclusion of water, Atmos. Chem. Phys., 9, 2919-2932, doi:10.5194/acp-9-2919-2009, 2009.