Integrated Experimental and Modeling Studies on Secondary Organic Aerosol Formation
EMSL Project ID
19836
Abstract
The objectives of this project are to: a) simultaneously characterize the time evolution of hydrocarbon precursor gases as well as the chemical and physical properties of secondary organic aerosols (SOA) using an existing 8-m3 aerosol chamber at PNNL, equipped with a suite of instruments available at EMSL, and b) link experimental data to the development and evaluation of theoretical models of SOA formation and aging. The requested EMSL instruments include the Proton Transfer Reaction Mass Spectrometer (PTRMS), Aerosol Mass Spectrometer (AMS), and Single Particle Laser Ablation Time-of-flight mass spectrometer (SPLAT). Additionally, Dr. Thornton will provide his Chemical Ionization Mass Spectrometer (UW-CIMS), which is a new instrument that is being developed to detect both gas-phase and aerosol-phase organic species. A series of carefully designed aerosol chamber experiments will be carried out to study SOA formation from photooxidation of -pinene and toluene (the most common biogenic and anthropogenic precursors, respectively) in the presence of varying amounts of pre-existing particles (e.g., monodisperse aerosols of ammonium sulfate, flame soot, oleic acid, lubricating oil, etc.). Comprehensive datasets to be obtained from the above mentioned measurements will allow us to determine the particle size distribution, particle density, gas-phase precursors, SOA yield and composition, and whether condensation of SOA species is driven by adsorption on the surface or by absorption in the bulk of the given primary seed aerosol. During the course of each experiment, the particles formed in the aerosol chamber will be continuously passed through a nephelometer and CCN chamber to simultaneously study the effects of SOA formation and aerosol aging on light scattering and CCN activity. Aerosol samples to be collected from the chamber experiments will also be examined using electron microscopy (TEM and SEM) and with the available GC/MS techniques to investigate the extent of in situ polymerization reactions as a source of SOA.
Experimental data will be evaluated using an explicit SOA model (based on Master Chemical Mechanism) being developed by Dr. Madronich in collaboration Dr. Zaveri, which will also be used to identify the principal oxidation products and guide the experimental design and measurements. We will also explore novel organic species lumping techniques to condense the explicit model so that the resulting surrogate model species can not only be directly compared and evaluated with field-deployable instruments such as the PTR-MS and AMS, but also be efficient enough for inclusion in 3-D Eulerian models.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2006-08-18
End Date
2009-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Vaden TD, C Song, RA Zaveri, D Imre, and A Zelenyuk. 2010. "Morphology of Mixed Primary and Secondary Organic Particles and the Adsorption of Spectator Organic Gases during Aerosol Formation." Proceedings of the National Academy of Sciences of the United States of America 107(15):6658-6663. doi:10.1073/pnas.0911206107
Zaveri RA, CM Berkowitz, FJ Brechtel, MK Gilles, JM Hubbe, JT Jayne, LI Kleinman, A Laskin, S Madronich, TB Onasch, MS Pekour, SR Springston, JA Thornton, AV Tivanski, and DR Worsnop. 2010. "Nighttime chemical evolution of aerosol and trace gases in a power plant plume: Implications for secondary organic nitrate and organosulfate aerosol formation, NO? radical chemistry, and N?O? heterogeneous hydrolysis." Journal of Geophysical Research. D. (Atmospheres) 115:Art. No. D12304. doi:10.1029/2009JD013250
Zelenyuk A, and D Imre. 2009. "Beyond single particle mass spectrometry: multidimensional characterisation of individual aerosol particles." International Reviews in Physical Chemistry 28(2):309-358.