1998 Progress Report: Emission and Fate of Biogenic Volatile Organic CompoundsEPA Grant Number: R825419
Title: Emission and Fate of Biogenic Volatile Organic Compounds
Investigators: Lamb, Brian , Claiborn, Candis , Westberg, Hal
Current Investigators: Lamb, Brian , Westberg, Hal
Institution: Washington State University
EPA Project Officer: Shapiro, Paul
Project Period: November 1, 1996 through October 31, 1999
Project Period Covered by this Report: November 1, 1997 through October 31, 1998
Project Amount: $372,986
RFA: Exploratory Research - Air Engineering (1996) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Land and Waste Management , Air , Engineering and Environmental Chemistry
Objective:The purpose of this work is to improve our understanding of the emissions of biogenic volatile organic compounds (BVOC) from vegetation and, in turn, to evaluate and improve the Biogenic Emission Inventory System (BEIS) as it is applied in various US locations.
Work during the past year has occurred in major two areas: 1) participation in a second PROPHET field program, and 2) incorporation of results from related research programs conducted at WSU. In the first area, WSU participated in the PROPHET 1998 summer intensive in north-central Michigan. PROPHET (Program for Research on Oxidants: PHotochemistry, Emissions and Transport) is a multi-investigator research effort with NARSTO affiliation that is aimed at understanding the formation and transport of photochemical air pollutants in the central US (http://aoss.engin.umich.edu/PROPHET/). The PROPHET field site is at the University of Michigan biological research station which is located in the midst of a mixed deciduous forest. During the summer field intensive, WSU conducted isoprene and terpene canopy-scale flux measurements using both a relaxed eddy accumulation (REA) system and a fast isoprene eddy covariance method Results from this work were presented at the spring AGU meeting in Boston, and at the STAR session of the AWMA Specialty Conference on Air Toxics at Research Triangle Park, NC.
In the second area, results from three other WSU research programs are being used in our overall effort to improve BEIS and as part of our contribution to the NARSTO assessment activities. First, seasonal isoprene emission rates were obtained during the summer and fall at a hybrid poplar plantation near Boardman, OR. Fluxes were measured using the WSU REA system and a fast isoprene eddy covariance system. These data are being used to test BEIS emission canopy models.
Second, terpene emissions data were collected using a branch cuvette system at an old growth Douglas fir forest in the Cascades of Washington state in conjunction with the Western Regional Global Climate Change Program sponsored by DOE. The goal of the program is to obtain a complete description of carbon cycling in this ecosystem. The unique feature of this work was access to the full height of the 60 m canopy using the Wind River Canopy Research Facility. Diurnal sampling was conducted on Douglas fir and western hemlock trees throughout the summer and fall, 1998. Visits to the site occurred at approximately 3.5 week intervals. Results from this work are being used to expand the BEIS data base for assigning standard emission factors for terpenes from these tree species and to determine the distribution of terpenes emitted from these species.
Third, WSU participated in the EPA Ozark Isoprene Experiment (OZIE) to investigate isoprene emissions and fate within the Ozark forests of southern Missouri during June, 1998. One of the goals of OZIE was aimed at relating isoprene surface concentrations to concentrations observed in the mixed layer. WSU measured isoprene and oxygenated VOC concentrations at approximately five surface sites selected to represent the approximate surface footprint upwind of the NCAR tethered balloon. NCAR simultaneously measured vertical profiles of isoprene concentration in the mixed layer. Results from this work will be used to help evaluate mixed layer flux estimates and to improve ways to evaluate photochemical grid models.
We obtained a very rich data set of eddy covarience data including heat flux, latent heat flux, CO2 flux and isoprene flux along with periodic REA flux measurements. Preliminary analyses of isoprene fluxes measured during the PROPHET field program show that isoprene fluxes exhibit a very high degree of correlation with sensible heat flux. This may provide a better way to model isoprene fluxes in regional ecosystem (land/air) exchange models. These data are undergoing further analysis and will be combined with all of the other PROPHET photochemical measurements to develop a complete description of isoprene photochemistry at the site.
Terpene emissions from Douglas fir and hemlock were in relatively good agreement with the values used in the current BEIS2 for these vegetation types. The distribution of terpenes emitted from Douglas fir were dominated (in order) by _-pinene, _3-carene, _-pinene, and limonene, while those from hemlock were dominated (in order ) by _-pinene, limonene, _-pinene, and myrcene.
Future Activities:Work will continue in each of the areas described above including continued participation in the PROPHET program, further work on the NARSTO assessment document and development of BEIS3, and additional effort to incorporate research results from related programs.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other project views:||All 24 publications||5 publications in selected types||All 5 journal articles|
||Guenther A, Geron C, Pierce T, Lamb B, Harley P, Fall R. Natural emissions of non-methane volatile organic compounds; carbon monoxide, and oxides of nitrogen from North America. Atmospheric Environment 2000;34(12-14):2205-223.0.||