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Comparative Evaluation of the Impact of WRF/NMM and WRF/ARW Meteorology on CMAQ Simulations for PM2.5 and its Related Precursors during the 2006 TexAQS/GoMACCS Study
Citation:
YU, S., R. MATHUR, J. E. PLEIM, G. POULIOT, D. C. WONG, B. K. EDER, K. L. SCHERE, R. C. GILLIAM, AND S. T. RAO. Comparative Evaluation of the Impact of WRF/NMM and WRF/ARW Meteorology on CMAQ Simulations for PM2.5 and its Related Precursors during the 2006 TexAQS/GoMACCS Study. Atmospheric Chemistry and Physics. Copernicus Publications, Katlenburg-Lindau, Germany, 12(9):4091-4106, (2012).
Impact/Purpose:
The National Exposure Research Laboratory′s (NERL′s) Atmospheric Modeling and Analysis Division (AMAD) conducts research in support of EPA′s mission to protect human health and the environment. AMAD′s research program is engaged in developing and evaluating predictive atmospheric models on all spatial and temporal scales for forecasting the Nation′s air quality and for assessing changes in air quality and air pollutant exposures, as affected by changes in ecosystem management and regulatory decisions. AMAD is responsible for providing a sound scientific and technical basis for regulatory policies based on air quality models to improve ambient air quality. The models developed by AMAD are being used by EPA, NOAA, and the air pollution community in understanding and forecasting not only the magnitude of the air pollution problem, but also in developing emission control policies and regulations for air quality improvements.
Description:
This study presents a comparative evaluation of the impact of WRF-NMM and WRF-ARW meteorology on CMAQ simulations of PM2.5, its composition and related precursors over the eastern United States with the intensive observations obtained by aircraft (NOAA WP-3), ship and surface monitoring networks (AIRNow, IMPROVE, CASTNet and STN) during the 2006 TexAQS/GoMACCS study. The results at the AIRNow surface sites show that both ARW-CMAQ and NMM-CMAQ reproduced day-today variations of observed PM2.5 and captured the majority of observed PM2.5 within a factor of 2 with a NMB value of −0.4% for ARW-CMAQ and −18% for NMM-CMAQ. Both models performed much better at the urban sites than at the rural sites, with greater underpredictions at the rural sites. Both models consistently underestimated the observed PM2.5 at the rural IMPROVE sites by −1% for the ARWCMAQ and −19% for the NMM-CMAQ. The greater underestimations of SO2-4, OC and EC by the NMM-CMAQ contributed to increased underestimation of PM2.5 at the IMPROVE sites. The NMB values for PM2.5 at the STN urban sites are 15% and −16% for the ARW-CMAQ and NMMCMAQ, respectively. The underestimation of PM2.5 at the STN sites by the NMM-CMAQ mainly results from the underestimations of the SO2−4 , NH+4 and TCM components, whereas the overestimation of PM2.5 at the STN sites by the ARW-CMAQ results from the overestimations of SO2−4 , NO−3 , and NH+4 . The Comparison with WP-3 aircraft measurements reveals that both ARW-CMAQ and NMM-CMAQ have very similar model performance for vertical profiles for PM2.5 chemical components SO2−4 NH+4 ) and related gaseous species (HNO3, SO2, NH3isoprene, toluene, terpenes) as both models used the same chemical mechanisms and emissions. The results of ship along the coast of southeastern Texas over the Gulf of Mexico show that both models captured the temporal variations and broad synoptic change seen in the observed HCHO and acetaldehyde with the means NMB <30% most of the time but they consistently underestimated terpenes, isoprene, toluene and SO2.
URLs/Downloads:
Atmospheric Chemistry and Physics
Comparative Evaluation of the Impact of WRF/NMM and WRF/ARW Meteorology on CMAQ Simulations for PM2.5 and its Related Precursors during the 2006 TexAQS GoMACCS Study (PDF, NA pp, 2115 KB, about PDF)