2008 Progress Report: SOA Volatility Evolution: Formation and Oxidation over the Lifecycle of PM2.5

EPA Grant Number: R833746
Title: SOA Volatility Evolution: Formation and Oxidation over the Lifecycle of PM2.5
Investigators: Donahue, Neil , Kroll, Jesse H. , Pandis, Spyros N. , Worsnop, Douglas R.
Institution: Carnegie Mellon University , Aerodyne Research Inc.
EPA Project Officer: Chung, Serena
Project Period: September 1, 2007 through August 31, 2011
Project Period Covered by this Report: September 1, 2007 through August 31,2008
Project Amount: $599,990
RFA: Sources and Atmospheric Formation of Organic Particulate Matter (2007) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air

Objective:

The objective of this project is to identify the major mechanisms for the aging of organic particulate matter in the atmosphere and to implement accurate parameterizations of those findings in air-quality models. In so doing, we strive to understand the relative contribution of human activity and natural emissions to organic aerosol levels and so to enable and inform policy actions aimed at organic-aerosol reductions.

Progress Summary:

We have made significant progress on both the experimental and laboratory aspects of this project. Two doctoral students, Kaytlin Henry (Chemical Eng., experimental) and Benjamin Murphy (Chemical Eng., modeling) are directly supported by the grant, while a third, Lea Hildebrandt (Chemical Eng., and Eng. Public Policy, experimental and policy), is an NSF fellow whose research falls under this project as well. Three undergraduate researchers, Christina Maksymiuk (Chemistry BS, 2008), Jyoti Bhapat (Chemistry) and Amy Maples (Chemical Eng.) have participated in project research. In the case of Christina Maksymiuk, her research led to a first-author paper currently under consideration for a special issue of Physical Chemistry, Chemical Physics devoted to organic aerosol chemistry. Engaging women and under-represented minorities in the physical sciences is an educational objective of our program:  two of the three doctoral students and all of the undergraduate researchers are women.

A notable experimental undertaking for 2008 was an intensive series of experiments in July 2008 involving the High-resolution Aerosol Mass Spectrometer operated by co-investigator Jesse Kroll at CMU for 3 weeks. We examined the interaction of anthropogenic and biogenic secondary organic aerosol by using an isotopic label on toluene (a major source of anthropogenic SOA) to separate it from alpha-pinene SOA, generating first one then the other SOA by oxidation of each precursor, and then observing the mixing behavior with high-resolution mass spectrometry.

During the remainder of the year, we separately investigated SOA formation from toluene, and alpha-pinene. We found significantly higher SOA yields than previous observations (confirming a recent finding from Caltech for low-NOx conditions and extending it to high-NOx conditions). A paper is under open discussion in ACPD on this topic (5 below). For alpha-pinene, we examined the volatility of SOA using thermal denuder measurements (paper 2 below) and also the influence of aging by exposure to OH radicals, which again showed significant changes in SOA concentrations, with an effect that appears to depend dramatically on the presence of UV light.

We have implemented the volatility basis set developed under our previous STAR grant in the air-quality model PMCAMx and investigated the effect of these aging reactions on SOA levels. The upshot is that increased SOA formation from toluene oxidation substantially improves model-measurement agreement, while enhanced SOA from a-pinene SOA aging is inconsistent with organic aerosol measurements in the southeastern United States (paper 3 below).

Future Activities:

We are continuing to explore the aging of biogenic SOA, using a-pinene as a model system. Activities include coordinated chamber experiments between CMU and the european EUROCHAMP network in a parallel (EUROCHAMP funded) project run by the PI in 2008-2009. Because dramatic OH aging effects appear to be sensitive to photochemistry, we are carrying out experiments in several European chambers with different traits, ranging from dark temperature control (the AiDA chamber in Karlsruhe) to simulated solar light (PSI in Zurich) to actual sunlight (SAPHIR in Juelich). The SAPHIR chamber also is sufficiently large to allow multiple-day aging experiments.

During the summer of 2009, we will conduct another intensive aging experiment at CMU, including the Aerodyne high-resolution AMS, with exact experiments depending on completion of the analysis of our current data and data from the EUROCHAMP project. In the mean time, aging experiments continue at CMU.

We are expanding our implementation of aging parameterizations in PMCAMx and other air-quality models, including an EPRI-funded implementation of the one-dimensional volatility basis set in CMAQ. Further, we are developing a two-dimensional version of the volatility basis set that incorporates the oxidation state of aerosol (O:C) in addition to volatility. This is already active and valuable for box-model simulations, and we are evaluating its utility for larger scale models.


Journal Articles on this Report : 5 Displayed | Download in RIS Format

Other project views: All 68 publications 31 publications in selected types All 31 journal articles
Type Citation Project Document Sources
Journal Article Cao G, Jang M. Secondary organic aerosol formation from toluene photooxidation under various NOx conditions and particle activity. Atmospheric Chemistry and Physics Discussions 2008;8(4):14467-14495. R833746 (2008)
  • Full-text: ACPD PDF
    Exit
  • Abstract: ACPD
    Exit
  • Journal Article Donahue NM, Robinson AL, Pandis SN. Atmospheric organic particulate matter: from smoke to secondary organic aerosol. Atmospheric Environment 2009;43(1):94-106. R833746 (2008)
    R833746 (2009)
    R833746 (2010)
    R833746 (Final)
    R833748 (2008)
    R833748 (2010)
    R833748 (Final)
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Journal Article Hallquist M, Wenger JC, Baltensperger U, Rudich Y, Simpson D, Claeys M, Dommen J, Donahue NM, George C, Goldstein AH, Hamilton JF, Herrmann H, Hoffmann T, Iinuma Y, Jang M, Jenkin ME, Jimenez JL, Kiendler-Scharr A, Maenhaut W, McFiggans G, Mentel TF, Monod A, Prevot ASH, Seinfeld JH, Surratt JD, Szmigielski R, Wildt J. The formation, properties and impact of secondary organic aerosol:current and emerging issues. Atmospheric Chemistry and Physics 2009;9(14):5155-5236. R833746 (2008)
    R833746 (2009)
    R833746 (2010)
    R833746 (Final)
    R833749 (2009)
    R833749 (Final)
  • Full-text: ACP-Full Text PDF
    Exit
  • Abstract: ACP-Abstract
    Exit
  • Other: CalTech-Full Text PDF
    Exit
  • Journal Article Lee B-H, Pierce JR, Engelhart GJ, Pandis SN. Volatility of secondary organic aerosol from the ozonolysis of monoterpenes. Atmospheric Environment 2011;45(14):2443-2452. R833746 (2008)
    R833746 (Final)
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Journal Article Murphy BN, Pandis SN. Simulating the formation of semivolatile primary and secondary organic aerosol in a regional chemical transport model. Environmental Science & Technology 2009;43(13):4722-4728. R833746 (2008)
    R833746 (2009)
    R833746 (2010)
    R833746 (Final)
    R833374 (Final)
  • Abstract from PubMed
  • Full-text: ES&T-Full Text HTML
    Exit
  • Abstract: ES&T-Abstract
    Exit
  • Other: ES&T-Full Text PDF
    Exit
  • Supplemental Keywords:

    Air Quality Modeling, Smog, Particulate Matter, Organics

    Relevant Websites:

    CAPS - Center for Atmospheric Particle Studies | Carnegie Mellon University Exit

    Progress and Final Reports:

    Original Abstract
  • 2009 Progress Report
  • 2010 Progress Report
  • Final Report