HR: 1340h
AN: A23B-1259    [Abstracts]
TI: Parameterisation of detailed aerosol processes
AU: * Topping, D
EM: david.topping@manchester.ac.uk
AF: School of Earth, atmospheric and environmental science, School of Earth, Atmospheric & Environmental Sciences The University of Manchester Simon Building Oxford Road Manchester M13 9PL, Manchester, M13 9PL, United Kingdom
AU: McFiggans, G
EM: g.mcfiggans@manchester.ac.uk
AF: School of Earth, atmospheric and environmental science, School of Earth, Atmospheric & Environmental Sciences The University of Manchester Simon Building Oxford Road Manchester M13 9PL, Manchester, M13 9PL, United Kingdom
AU: Coe, H
EM: hugh.coe@manchester.ac.uk
AF: School of Earth, atmospheric and environmental science, School of Earth, Atmospheric & Environmental Sciences The University of Manchester Simon Building Oxford Road Manchester M13 9PL, Manchester, M13 9PL, United Kingdom
AB: Modelling the equilibrium composition and phase state of aqueous aerosols is a complex challenge requiring the use of fundamental frameworks that can deal with the composition variability of mixed inorganic/organic aerosol where appropriate laboratory data is lacking. Such a framework was developed at the University of Manchester which is often used as a closure and prognostic tool for studies of aerosol particle hygroscopicity and gas/particle phase partitioning (ADDEM – Aerosol Diameter Dependent Equilibrium Model). However, large scale models, which are used in impacts and effects studies, are computationally expensive and cannot treat all the relevant physical/chemical processes taking place in the atmosphere which much complexity. Thus, there is still a need for developing links across the hierarchy of model frameworks between so called ‘bottom up' and ‘top down' modelling approaches. With this in mind, key variables have been parameterised for use in predicting both the hygroscopic properties and gas/particle partitioning in large scale models. Developments of appropriate parameterisations are challenging mathematically as one ideally requires a generic model that retains variables with physical/chemical significance. Similarly, the nature of aqueous atmospheric aerosol particles is such that processes taking place within a liquid phase often require iterative steps depending on the chemical composition, further increasing the computational complexity of any ‘simplified' framework. Whilst challenging mathematically, the framework developed here is such that any number of dimensions (chemical components) can be added for future developments and the nature of parameter fitting has allowed one to bypass the above mentioned iterative steps. These modules provide a direct output of detailed processes studies continually carried out within the area of aerosol dynamics. Indeed, this development means we can now directly exploit important future fundamental process studies when attempting to asses large scale impacts by incorporation of appropriate data into the above parameterisations.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting