Final 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
EPA Project Officer: Hunt, Sherri
Project Period: April 1, 2013 through March 31, 2017
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 and Ziemann groups have completed the field measurements with the following outputs: (1) fine particle composition using FTIR, XRF, and AMS techniques as part of the SOAS campaign at the Centerville, AL, and Look Rock, TN, sites during June and July of 2013; (2) source apportionment of AMS, FTIR and single particle AMS clusters; and (3) interpretation of the atmospheric processes that affected the field measurements. The environmental chamber experiments forming secondary organic aerosol (SOA) from reactions of atmospheric oxidants were designed based on VOCs measured during the SOAS campaign and completed. The outputs are the organic functional group compositions from these chamber experiments using derivatization-spectrophotometric methods as well as FTIR and the molecular composition using liquid chromatography with chemical ionization-ion trap mass spectrometry.
The key findings from this project are:
Selective Uptake of bSOA on Sulfate-Containing Particles at Look Rock, TN
Organic aerosol concentrations were enhanced by multi-day accumulation of isoprene-related secondary particle products at Look Rock, Tennessee, during SOAS in 2013.
Three types of single particle composition had mass fragments similar to three mass-weighted aerosol mass spectrometer composition factors, providing clear signatures of biogenic and man-made aerosol components.
Isoprene-related organic aerosol mass fragments were mostly found on sulfate-containing particles, indicating selective uptake of additional bSOA to particles driven by sulfate from power plants.
Different Levels of NOx at Look Rock, TN, and Centerville, AL, affect bSOA
Aerosol concentrations and chemical compositions at two different forested sites (Look Rock, TN, and Centerville, AL) in summertime southeastern U.S. were generally similar during SOAS in 2013.
FTIR spectra of biogenic factors from positive matrix factorization are very similar to bSOA from isoprene chamber experiments.
The lower NOx at Look Rock gives less nighttime SOA formation but higher hygroscopicity than at Centreville.
Patterns in the relative amounts of nitrate, carbonyl, carboxyl, alcohol, ester, peroxide, and alkane functional groups and their infrared spectroscopic profiles are characteristic of biogenic SOA formed from two of the major potential pathways expected for the SOAS study: daytime reactions of isoprene and/or monoterpenes with OH under high NOx (polluted) conditions, and nighttime reactions of monoterpenes with NO3.
Features in the functional group composition and infrared spectra that indicate the influence of NOx and SOx on SOA composition.
Daytime high NOx reactions of isoprene with OH and nighttime reactions of monoterpenes with NO3 both form organic nitrates, but can be distinguished based on the presence or absence of carboxyl, alcohol, and ester groups.
The influence of SOx on SOA formation was indicated by the presence of ester groups, which are usually formed through particle-phase reactions that require an acid catalyst that would be H2SO4 at the SOAS sites.
By using the insights gained from laboratory studies we were then able to interpret the functional group composition and infrared spectra of SOAS samples in terms of potential SOA sources.
The observation that all SOAS samples analyzed contained significant fractions of carboxyl, ester, and alcohol groups and relatively little ketone/aldehyde groups indicates that the SOA contained a significant contribution from reactions of isoprene with OH under high NOx conditions.
The high abundance of ester groups was strong evidence that particle-phase reactions were significant, either acid-catalyzed reactions of carboxyl and alcohol groups or oxidation of ketones by hydroperoxides.
These results show the significance of heterogeneous reactions on sulfate particles from anthropogenic emissions for bSOA and specifically link the near doubling of bSOA to sulfate from power plants in the region. In addition, they show that higher NOx from vehicle emissions produces more nighttime bSOA and less hygroscopic, more absorbing particles at Centreville than at Look Rock.
The data collected by the Russell, Bertram, Cappa, and McKinney groups that were collected in the Russell sampling van funded by this grant are curated at the following archives and have been shared with GRSM-01133 as part of our agreement with Great Smoky Mountains National Park:
Lynn M. Russell, Timothy H. Bertram, Christopher D. Cappa, Karena A. McKinney, Jun Liu, Ying Liu, Yingjun Liu, Scot T. Martin, Xiaolu Zhang, Kathryn J. Zimmerman, Carbonaceous Aerosol Particle Measurements from Southeast Atmosphere Study (SOAS) 2013 in Look Rock, Tennessee, USA. UCSD LIBRARY DIGITAL COLLECTIONS, DOI: http://doi.org/10.6075/J0P26W1T.
Lynn M. Russell, Jun Liu, Carbonaceous Aerosol Particle Measurements from Southeast Atmosphere Study (SOAS) 2013 in Look Rock, Tennessee, USA, https://esrl.noaa.gov/csd/groups/csd7/measurements/2013senex/LRK/DataDownload/index.php?page=/csd/groups/csd7/measurements/2013senex/LRK/DataDownload/.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other project views:||All 9 publications||1 publications in selected types||All 1 journal articles|
||Liu J, Russell LM, Lee AKY, McKinney KA, Surratt JD, Ziemann PJ. Observational evidence for pollution-influenced selective uptake contributing to biogenic secondary organic aerosols in the southeastern U.S. Geophysical Research Letters 2017;44(15):8056-8064.||
fine particles, secondary organic aerosol, PM2.5, isoprene, nitrogen oxides, oxidation, mass spectrometry
Progress and Final Reports:Original Abstract
2013 Progress Report
2014 Progress Report
2015 Progress Report