Process based Modelling of Chemical and Physical Aerosol Properties Relevant for Climate and Health
Author
Summary, in English
The first is a 2D-Lagrangian model for Aerosol Dynamics, gas phase CHEMistry and radiative transfer (ADCHEM), which treats the dispersion in the vertical and horizontal direction perpendicular to air mass trajectories. The second model is a kinetic multilayer model for Aerosol Dynamics, gas and particle phase chemistry in laboratory CHAMber environments (ADCHAM). With ADCHAM it is possible to study process based formation and evaporation of secondary organic aerosol particles, and mass transfer limitations and reactions within the particle phase.
ADCHEM was used to quantify the anthropogenic influence from the city of Malmö (280 000 inhabitants) in southern Sweden. In Malmö and a few tens of kilometres downwind, the primary particle emissions have a large influence on the particle number concentration. However, more than 2 hours downwind Malmö, the anthropogenic particle mass contribution is dominated by secondary ammonium nitrate. To quantify the direct and indirect climate impact of urban aerosol emissions, the secondary aerosol formation which changes the optical and hygroscopic properties of the primary soot particles, needs to be addressed in future measurements and process modelling.
ADCHAM was used to simulate different laboratory chamber experiment, with focus on potential influential but poorly known processes for secondary organic aerosol properties, formation and evaporation rates in the atmosphere (i.e. oligomerization, organic salt formation, salting-out effects, oxidation of organic compounds in the particle phase and mass transfer limitations in the particle phase). The model results reveal that formation of small amounts of low-volatile and long lived oligomers, which accumulate in the particle surface layers, can effectively prevent the evaporation of more volatile compounds. This can significantly prolong the lifetime of SOA in the atmosphere.
Publishing year
2013
Language
English
Full text
- Available as PDF - 17 MB
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Document type
Dissertation
Publisher
Division of Nuclear Physics, Department of Physics Box 118, SE-221 00 Lund
Topic
- Subatomic Physics
Keywords
- gas phase chemistry
- aerosol dynamics
- aerosol particles
- climate
- kinetic multilayer model
- Fysicumarkivet A:2013:Roldin
Status
Published
Research group
- Aerosol, Nuclear Physics
Supervisor
ISBN/ISSN/Other
- ISBN: 978-91-7473-535-2
Defence date
31 May 2013
Defence time
13:15
Defence place
Lecture hall Rydbergsalen, Department of Physics, Sölvegatan 14, Lund University Faculty of Engineering
Opponent
- Hannele Korhonen