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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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Evaluating Regional Emission Estimates Using Field Observations
G.R. Carmichael1, Y. Tang1 , G. Kurata3 , I. Uno2, D.G. Streets4 , N. Thongboonchoo1, J-H Woo1, S. Guttikundi1, A. White11, T. Wang15, D.R. Blake6, E. Atlas5 A. Fried5, B. Potter8, M.A. Avery7,G.W. Sachse7, S.T. Sandholm9, Y. Kondo10, R.W. Talbot12, A. Bandy13, D. Thorton13, A.D. Clarke14
1 Center for Global and Regional Environmental Research, University of Iowa, Iowa, USA
2 Research Institute for Applied Mechanics, Kyushu University, Fukuoka, Japan
3 Department of Ecological Engineering, Toyohashi University of Technology, Toyohashi, Japan
4 Decision and Information Sciences Division, Argonne National Laboratory, Argonne, IL, USA
5 National Center for Atmospheric Research, Colorado, USA
6 Department of Chemistry, University of California at Irvine, California, USA
7 NASA Langley Center, Virginia, USA
8 University of Tulsa, Oklahoma, USA
9 Georgia Institute of Technology, Georgia, USA
10 Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, Japan
11 Department of Chemical Engineering, University of California at Davis, California, USA
12 Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, New Hampshire, USA
13 Chemistry Department, Drexel University, Pennsylvania, USA
14 School of Ocean and Earth Science and Technology, University of Hawaii, Hawaii, USA
15 Polytechnic University, Hong Kong, China
This paper focuses on techniques to integrate field studies, with models and emission estimates to evaluate and improve emissions. Measurements obtained during the NASA TRACE-P, NSF Ace-Asia, and NOAA-ITCT-2K1 experiments are used in conjunction with regional modeling analysis to evaluate emission estimates for Asia. A comparison between the modeled values and the observations is one method to evaluate emissions. Based on such analysis it is concluded that the inventory performs well for the light alkanes, CO, ethylene, SO2, NOx. Furthermore, based on model skill in predicting important photochemical species such as O3, HCHO, OH, HO2, and HNO3, it is found that the emissions inventories are of sufficient quality to support preliminary studies of ozone production. These are important finding in light of the fact that emission estimates for many species (such as speciated NMHCs and BC) for this region have only recently been estimated and are highly uncertain. Using a classification of the measurements built upon trajectory analysis, we compare observed species distributions, and ratios of species, to those modeled, and to ratios estimated from the emissions inventory. It is shown that this technique can reconstruct a spatial distribution of propane/benzene that looks remarkably similar to that calculated from the emissions inventory. A major discrepancy between modeled and observed behavior is found in the Yellow Sea, where modeled values are systematically under-predicted. The integrated analysis suggests that this may be related to an under-estimation of emissions from the domestic sector. The emission is further tested by comparing observed and measured species ratios in identified megacity plumes. Many of the model derived ratios (e.g., BC/CO, SOx/C2H2) fall within ~25% of those observed, and all fall outside of a factor of 2.5. Discussion of how these techniques could be used in support of upcoming experiments in North America will also be presented.