Skip to content
Journal article

Impact of model resolution on chemical ozone formation in Mexico City: Application of the WRF-Chem model

Tie X, Brasseur G, Ying Z ...see all

Atmospheric Chemistry and Physics, vol. 10, issue 18 (2010) pp. 8983-8995

  • 31

    Readers

    Mendeley users who have this article in their library.
  • 30

    Citations

    Citations of this article.
  • N/A

    Views

    ScienceDirect users who have downloaded this article.
Sign in to save reference

Abstract

The resolution of regional chemical/dynamical models has important effects on the calculation of the distri-butions of air pollutants in urban areas. In this study, the sen-sitivity of air pollutants and photochemical ozone production to different model resolutions is assessed by applying a re-gional chemical/dynamical model (version 3 of Weather Re-search and Forecasting Chemical model – WRF-Chemv3) to the case of Mexico City. The model results with 3, 6, 12, and 24 km resolutions are compared to local surface measure-ments of CO, NO x , and O 3 . The study shows that the model resolutions of 3 and 6 km provide reasonable simulations of surface CO, NO x , and O 3 concentrations and of diurnal vari-ations. The model tends to underestimate the measurements when the resolution is reduced to 12 km or less. The cal-culated surface CO, NO x , and O 3 concentrations at 24 km resolution are significantly lower than measured values. This study suggests that the ratio of the city size to the thresh-old resolution is 6 to 1, and that this ratio can be considered as a test value in other urban areas for model resolution set-ting. There are three major factors related to the effects of model resolution on the calculations of O 3 and O 3 precur-sors, including; (1) the calculated meteorological conditions, (2) the spatial distribution for the emissions of ozone precur-sors, and (3) the non-linearity in the photochemical ozone production. Model studies suggest that, for the calculations of O 3 and O 3 precursors, spatial resolutions (resulting from different meteorological condition and transport processes) have larger impacts than the effect of the resolution associ-ated with emission inventories. The model shows that, with coarse resolution of emission inventory (24 km) and high res-Correspondence to: X. Tie (xxtie@ucar.edu) olution for meteorological conditions (6 km), the calculated CO and O 3 are considerably improved compared to the re-sults obtained with coarse resolution for both emission in-ventory and meteorological conditions (24 km). The resolu-tion of the surface emissions has important effects on the cal-culated concentration fields, but the effects are smaller than those resulting from the model resolution. This study also suggests that the effect of model resolution on O 3 precursors leads to important impacts on the photochemical formation of ozone. This results directly from the non-linear relation-ship between O 3 formation and O 3 precursor concentrations. Finally, this study suggests that, considering the balance be-tween model performance and required computation time on current computers, the 6 km resolution is an optimal resolu-tion for the calculation of ozone and its precursors in urban areas like Mexico City.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

  • X. Tie

  • G. Brasseur

  • Z. Ying

Cite this document

Choose a citation style from the tabs below