在线阅读

在线阅读

Partic. vol. 40 pp. 88-97 (October 2018)
doi: 10.1016/j.partic.2017.10.005

Comparative evaluation of the impact of GRAPES and MM5 meteorology on CMAQ prediction over Pearl River Delta, China

Tao Denga,*, Yiang Chena,b, Qilin Wana, Yanxia Zhanga, Xuejiao Denga, Yanyan Huanga, Guangfeng Daia, Fei Lia

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tdeng@grmc.gov.cn

Highlights

    • Air quality forecasting of GRAPES-CMAQ and MM5-CMAQ was assessed. • Both models had similar good performance with better performance by GRAPES-CMAQ. • Underestimations of nitrate and ammonium salt contributed to underestimations of PM2.5. • Effect of meteorological factors and physical–chemical processes on forecast results was discussed.

Abstract

The community multiscale air quality (CMAQ) model was used to forecast air quality over the Pearl River Delta region from December 2013 to January 2014. The pollution forecasting performance of CMAQ coupled with two different meteorological models, i.e., the global/regional assimilation and prediction system (GRAPES) and the fifth-generation mesoscale model (MM5), was assessed by comparison with observational data. The effects of meteorological factors and physicochemical processes on the forecast results were discussed through process analysis. The results showed that both models exhibited good performance but that of GRAPES-CMAQ was better. GRAPES was superior in predicting the overall variation tendencies of meteorological fields, but it showed large deviations in atmospheric pressure and wind speed. This contributed to the higher correlation coefficients of the pollutants with GRAPES-CMAQ but with greater deviations. The underestimations of nitrate and ammonium salt contributed to the underestimations of both particulate matter and extinction coefficients. Source emissions made the only positive contributions to surface layer SO2, CO, and NO. It was found that O3 originated primarily from horizontal and vertical transport and that its consumption was predominantly via chemical processes. Conversely, NO2 was found derived primarily from chemical production.

Graphical abstract

Keywords

Air quality; Numerical simulation; Global/regional assimilation and prediction system (GRAPES); Community multiscale air quality (CMAQ); Process analysis