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NARSTO Workshop on Innovative Methods for Emission Inventory Development and Evaluation University of Texas, Austin October 14-17, 2003 |
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Measuring Trace Gas Fluxes from an Aircraft Platform
Paul V. Doskey, V. Rao Kotamarthi, Mikhail S. Pekour, David R. Cook, and Michael T. Ritsche
Environmental Research Division, Argonne National Laboratory, Argonne, Illinois
B. Tom Jobson and John Hubbe
Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory
Work at Argonne National Laboratory supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, Climate Change Research Division, under contract W-31-109-Eng-38.
The submitted manuscript has been created by the University of Chicago as operator of Argonne National Laboratory under Contract No. W-31-109-ENG-38 with the U.S. Department of Energy. The U.S. government retains for itself, and others acting on its behalf, a paid-up, nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the government.
Nonmethane organic compounds (NMOCs) are precursors to ozone and aerosol formation. Global-scale emissions of NMOCs from biogenic and anthropogenic sources are approximately 1200 and 130 Tg C a-1, respectively. Evaluations of NMOC emission inventories developed for rural and urban areas (which contain large uncertainties) necessitate direct measurement of landscape-scale fluxes. The main objectives of this research are (1) to develop aircraft-based methodologies for measuring the rate of exchange of NMOCs with environmental surfaces and (2) to make observations of the vertical flux and concentration profiles of NMOCs and their oxidation products above urban and rural landscapes in order to evaluate chemical-transport models and emission inventories. The measurement approach uses a variety of eddy sampling techniques in concert with fast- and slow-response chemical and turbulence sensors to determine air-surface exchange rates. A description of the eddy sampling techniques and sensors will be presented. In addition, results from a field experiment designed to measure the flux of isoprene from a forested site will be described.