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DIAGNOSTIC EVALUATION OF CMAQ RESPONSE OF INORGANIC FINE PARTICULATE SPECIES OF EMISSIONS CHANGES
Citation:
Dennis, R L., S J. Roselle, C Nolte, AND P. Bhave. DIAGNOSTIC EVALUATION OF CMAQ RESPONSE OF INORGANIC FINE PARTICULATE SPECIES OF EMISSIONS CHANGES. Presented at 2004 Models-3 Conference, ChapelHill, NC, October 18-20, 2004.
Impact/Purpose:
The goal of this task is to thoroughly characterize the performance of the emissions, meteorological and chemical/transport modeling components of the Models-3 system, with an emphasis on the chemical/transport model, CMAQ. Emissions-based models are composed of highly complex scientific hypotheses concerning natural processes that can be evaluated through comparison with observations, but not validated. Both performance and diagnostic evaluation together with sensitivity analyses are needed to establish credibility and build confidence within the client and scientific community in the simulations results for policy and scientific applications. The characterization of the performance of Models-3/CMAQ is also a tool for the model developers to identify aspects of the modeling system that require further improvement.
Description:
The Gas Ratio proposed by Spyros Pandis, which identifies whether the system is nitric acid or ammonia limited, is an indicator of the sensitivity of the inorganic system to changes in conditions. This indicator is investigated in this work to find out how well it can diagnose sensitivity of the model with respect to changes in inorganic emissions. First, a sense of CMAQ's performance on the Gas Ratio indicator is presented, showing the range over which reasonable performance is obtained, and showing how bias in the individual species of the indicator can affect the indicator. Then a model study of the sensitivity of the Gas Ratio to changes in inorganic emissions and how this translates to the degree of nitrate replacement for reductions in sulfate is presented. An examination of how potential errors in the ammonia emissions inventory in the desert West and the very upper Mid-west could be affecting the predicted response of CMAQ to emissions changes will complete the talk.
The research presented here was performed under the Memorandum of Understanding between the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) under agreement number DW13921548. Although it has been reviewed by EPA and NOAA and approved for publication, it does not necessarily reflect their policies or views.