2014 Progress Report: Using Particle Functional Group Composition to Identify and Quantify the Effects of Anthropogenic Emissions on Biogenic Secondary Organic AerosolEPA Grant Number: R835408
Title: Using Particle Functional Group Composition to Identify and Quantify the Effects of Anthropogenic Emissions on Biogenic Secondary Organic Aerosol
Investigators: Russell, Lynn M , Ziemann, Paul J.
Institution: University of California - San Diego , University of Colorado at Boulder
Current Institution: University of California - San Diego , University of Colorado at Boulder
EPA Project Officer: Chung, Serena
Project Period: April 1, 2013 through March 31, 2017
Project Period Covered by this Report: April 1, 2014 through March 31,2015
Project Amount: $400,000
RFA: Anthropogenic Influences on Organic Aerosol Formation and Regional Climate Implications (2012) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Global Climate Change , Climate Change , Air
This research project combines ambient measurements and environmental chamber experiments on organic aerosols to identify and quantify the effects of anthropogenic inorganic and organic emissions on biogenic secondary organic aerosol (bSOA) formed in the Southern Oxidants and Aerosol Study (SOAS) in Summer 2013. This objective will be met by completing the following tasks: (1) identify and quantify the organic functional group (OFG) compositions and infrared spectroscopic features of bSOA in samples collected as part of SOAS; (2) determine the effects of NOx, SOx, and anthropogenic volatile organic compounds (VOCs) on the characteristic functional group and spectroscopic features of bSOA formed from reactions of biogenic volatile organic compounds (bVOC), and on the SOA yields; and (3) interpret the functional group compositions and infrared spectroscopic features of SOAS organic aerosol samples using results of laboratory experiments and ambient measurements of other relevant aerosol and gas properties in order to identify and quantify the contributions of biogenic and anthropogenic emissions to SOA formed during the study.
The Russell group has completed measurements that contribute to all three of the tasks that constitute this project. Specifically, the Russell group collected measurements of fine particle composition using Fourier transform Infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and aerosol mass spectrometry (AMS) techniques as part of the SOAS campaign at the Centerville, AL, and Look Rock, TN, sites during June and July of 2013. The Russell group collected fine particle mass on Teflon filters for quantification of organic functional group concentrations by FTIR spectroscopy and elemental concentrations by X-ray fluorescence (XRF). These results provide quantitative characterization of the organic composition of fine aerosol and the identification of source categories and quantitative source contributions through the use of elemental tracers and positive matrix factorization (PMF). At Look Rock, TN, the sample collection was conducted alongside simultaneous high resolution, time of flight aerosol mass spectrometer (HR-TOF-AMS) measurements, which provides total organic mass and complementary information on organic composition (mass spectral fragments).
In August 2013, Dr. Ziemann moved from the University of California, Riverside (UCR) to the University of Colorado, Boulder, where he now is a professor in the Department of Chemistry and Biochemistry and a fellow in the Cooperative Institute for Research in Environmental Sciences (CIRES). This move has delayed the laboratory research originally planned for Year 1 of the project. Dr. Ziemann's new laboratory now is set up and operating, and contains all the analytical instruments and environmental chambers he had available for the project at UCR, in addition to new equipment he has purchased with start-up funds and access to two new temperature-controlled chambers that are part of a new Atmospheric Chemistry Facility. Graduate student Megan Claflin has been working to adapt derivatization-spectrophotometric methods used routinely by the Ziemann group for functional group analysis for use with microgram samples by employing a nanospectrophotometer.
The expected results of this project include: (1) improved chemical characterization of biogenic SOA in the southeastern United States, (2) improved quantification of biogenic SOA in the southeastern United States, (3) improved understanding of the effects of pollutants on biogenic SOA composition and yield, and (4) improved understanding of the reactions that control biogenic SOA composition and yield.
The project schedule is generally on track to be completed with a 1-year no-cost extension. The SOAS field experiment was completed as scheduled and the results were processed and analyzed during the first year. In Year 2, the Russell group continued analyzing the results of the SOAS field campaign and provided filters for SOA chamber samples in collaboration with the Ziemann group. In Year 3, laboratory studies will be conducted under the conditions described above to obtain data on SOA functional group and molecular composition that will be used to develop SOA source signatures to aid in the interpretation of FTIR analyses of filter samples that were collected in the SOAS field campaign in 2013. Selected filter samples from that campaign also will be analyzed using derivatization-spectrophotometric methods. The SOA also will be analyzed using a suite of mass spectrometric methods to gain additional information on chemical composition. In Year 3, the Russell group will continue analyzing the results of the SOAS field campaign and will provide and analyze SOA chamber samples in collaboration with the Ziemann group. In Year 3, additional laboratory studies will be conducted under the conditions described above to obtain data on SOA functional group and molecular composition that will be used to develop SOA source signatures to aid in the interpretation of FTIR analyses of filter samples that were collected in the SOAS field campaign in 2013. Selected filter samples from that campaign also will be analyzed using derivatization spectrophotometric methods.
Journal Articles:No journal articles submitted with this report: View all 10 publications for this project
Fine particles, secondary organic aerosol, PM2.5, isoprene, nitrogen oxides, oxidation, mass spectrometry, FTIR, AMS, XRF, HR-TOF-AMS