![[logo] US EPA](https://webarchive.library.unt.edu/eot2008/20081107125259im_/http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
2006 Progress Report: Atmospheric Aerosols from Biogenic Hydrocarbon Oxidation
EPA Grant Number: R831079Title: Atmospheric Aerosols from Biogenic Hydrocarbon Oxidation
Investigators: Milford, Jana B. , Guenther, Alex , Helmig, Detlev , Wiedinmyer, Christine
Institution: University of Colorado at Boulder , National Center for Atmospheric Research
EPA Project Officer: Winner, Darrell
Project Period: October 1, 2003 through September 30, 2006 (Extended to September 30, 2007)
Project Period Covered by this Report: October 1, 2005 through September 30, 2006
Project Amount: $440,000
RFA: Measurement, Modeling, and Analysis Methods for Airborne Carbonaceous Fine Particulate Matter (PM2.5) (2003)
Research Category: Air Quality and Air Toxics , Particulate Matter
Description:
Objective:The objective of our research is to estimate contributions of biogenic volatile organic compounds (BVOC), especially monoterpenes and sesquiterpenes, to secondary aerosol production in the eastern United States.
Progress Summary:The research project includes studies of sesquiterpene emissions; incorporation of biogenic emissions into the Model of Emissions of Gases and Aerosol from Nature (MEGAN); development of BVOC emission inventories for base case and future land-use scenarios; and regional-scale air quality modeling using these inventories in the Community Multiscale Air Quality Model (CMAQ). During the third year of the project our work continued to focus on emissions measurements, further development of MEGAN, and development and preliminary modeling with CMAQ.
Work has continued on calculating biogenic emissions using the MEGAN framework to produce CMAQ-ready emissions files. These procedures include geographical information system (GIS) processing of MEGAN input files and use of FORTRAN90 modules to create IO/API hourly emissions files. Sesquiterpene emissions factors used with MEGAN have been updated to reflect recent data including measurements made under this grant. Schemes have been developed to apportion detailed MEGAN species to the VOC classes used in four widely used chemical mechanisms.
The CMAQ model was further modified to include known gas-phase products of sesquiterpene oxidation along with secondary organic aerosol (SOA) formation. The model has also been modified to allow the option of treating a portion of the SOA as polymerized aerosol that is not susceptible to evaporation, for sensitivity analysis. Previous work on evaluation of CMAQ results has been extended by developing the capability of comparing model results to estimated secondary organic carbon (OC) based on comparison with primary OC to elemental carbon (EC) ratios, and utilization of C-14 data to distinguish fossil and modern carbon components.
Emission studies were continued during May to September 2006 at the NCAR greenhouse and Creekside Nursery in Boulder, CO. A total of 36 enclosure measurements were performed, including measurements of emissions from shrubs, trees, and several crops. Analysis of data from these experiments is continuing.
Future Activities:In the coming year, analysis of monoterpenes and sesquiterpenes data from enclosure studies performed in 2006 will be completed and results will be prepared for publication. We will finish updating the biogenic sesquiterpene (SQT) emission estimates within the MEGAN framework, and run CMAQ with these new estimates. CMAQ results will be evaluated by comparison to observations, including using the OC/EC method and C-14 data to help assess SOA predictions. Sensitivity analysis will be performed to explore the influence of SQT emissions estimates and SOA partioning parameters, with diagnostic analysis used to better understand the meteorological and chemical conditions where SQT contributions are likely to be most important. Finally, MEGAN and CMAQ will be used to assess the response of SQT emissions and SOA formation to alternative land-use scenarios. The results of these modeling analyses will be written up for publication in a Ph.D. thesis and journal articles.
Journal Articles on this Report: 2 Displayed | Download in RIS Format
| Other project views: | All 16 publications | 5 publications in selected types | All 5 journal articles |
| Type | Citation | ||
|---|---|---|---|
|
|
Helmig D, Ortega J, Guenther A, Herrick JD, Geron C. Sesquiterpene emissions from loblolly pine and their potential contribution to biogenic aerosol formation in the Southeastern US. Atmospheric Environment 2006;40(22):4150-4157. |
R831079 (2006) R831079 (Final) |
|
|
|
Helmig D, Ortega J, Duhl T, Tanner D, Guenther A, Harley P, Wiedinmyer C, Milford J, Sakulyanontvittaya T. Sesquiterpene emissions from pine trees—identifications, emission rates and flux estimates for the contiguous United States. Environmental Science & Technology 2007;41(5):1545-1553. |
R831079 (2006) R831079 (Final) |
|
biogenic hydrocarbons, secondary organic aerosols, sesquiterpenes,
,
Ecosystem Protection/Environmental Exposure & Risk, Air, Scientific Discipline, RFA, Analytical Chemistry, Air Pollution Effects, air toxics, Atmospheric Sciences, Environmental Engineering, particulate matter, Environmental Chemistry, Monitoring/Modeling, Environmental Monitoring, mass spectrometry, aerosol analyzers, health effects, Volatile Organic Compounds (VOCs), carbon particles, particulate matter mass, measurement methods, aerosol particles, air sampling, emissions, biogenic hydrocarbon oxidation, air quality models, atmospheric particulate matter, thermal desorption
Relevant Websites:
http://bai.acd.ucar.edu/Megan/index.shtml
Progress and Final Reports:
2004 Progress Report
2005 Progress Report
Original Abstract
Final Report