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Modeling Non-Methane Hydrocarbon Emissions from Forest CanopiesEPA Grant Number: GF9500040
Title: Modeling Non-Methane Hydrocarbon Emissions from Forest Canopies
Investigators: Bowling, David R.
Institution: University of Colorado
EPA Project Officer: Broadway, Virginia
Project Period: September 1, 1995 through January 1, 2000
Project Amount: $32,700
RFA: STAR Graduate Fellowships (1995) Recipients Lists
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Earth
The purpose of this project is to investigate various environmental controls on hydrocarbon emissions at the forest canopy level, and the influence of hydrocarbon emissions on tropospheric chemistry. The results of this study will be used to determine what factors are necessary to adequately predict hydrocarbon emissions, specifically, isoprene and monoterpene, at canopy, ecosystem, and regional levels, and to develop and validate predictive models for these forest hydrocarbon emissions. The specific approach under this study includes: 1) development of a canopy-level model for coniferous forest emissions, 2) development of a phenology model for basal emission rate, and 3) integration of the canopy and phenology models into chemical transport models. The approach includes conducting field measurements of canopy microclimate (light, temperature, etc.) and hydrocarbon emission rates for stands of spruce, fir, and aspen in the Rocky Mountains, and white and black spruce in Canada. The study will evaluate measurements taken over two to three growing seasons. To allow adequate eddy correlation flux measurements at rates slower than 10 Hz, the project will use a relaxed eddy accumulator (REA) being developed in cooperation with the National Center for Atmospheric Research. Following collection of measurement data, standard leaf level temperature/light algorithms will be modified to address canopy level inputs and will be combined with land use data to produce and emission inventory. After validation of the canopy model, the results will be extended to larger scales using a transport model such as the EPA Regional Oxidant Model. Biogenic hydrocarbon emissions have a significant effect on tropospheric chemistry and accurate models of forest hydrocarbon emission are required to adequately understand regional ozone pollution and predict response of the atmosphere to future global change. This project will improve understanding of the factors that control non-methane hydrocarbon emissions at the forest canopy level, and will provide policymakers with the information necessary to assess the significance of biological hydrocarbon emissions.