Articles | Volume 9, issue 13
Atmos. Chem. Phys., 9, 4419–4438, 2009

Special issue: MILAGRO/INTEX-B 2006

Atmos. Chem. Phys., 9, 4419–4438, 2009

  07 Jul 2009

07 Jul 2009

Evaluation of WRF mesoscale simulations and particle trajectory analysis for the MILAGRO field campaign

B. de Foy1, M. Zavala2,3, N. Bei2,3, and L. T. Molina2,3 B. de Foy et al.
  • 1Department of Earth and Atmospheric Sciences, Saint Louis University, MO, USA
  • 2Molina Center for Energy and the Environment, CA, USA
  • 3Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, MA, USA

Abstract. Accurate numerical simulations of the complex wind flows in the Mexico City Metropolitan Area (MCMA) can be an invaluable tool for interpreting the MILAGRO field campaign results. This paper uses three methods to evaluate numerical simulations of basin meteorology using the MM5 and WRF models: statistical comparisons with observations, "Concentration Field Analysis" (CFA) using measured air pollutant concentrations, and comparison of flow features using cluster analysis. CFA is shown to be a better indication of simulation quality than statistical metrics, and WRF simulations are shown to be an improvement on the MM5 ones. Comparisons with clusters identifies an under-representation of the drainage flows into the basin and an over-representation of wind shear in the boundary layer. Particle trajectories simulated with WRF-FLEXPART are then used to analyse the transport of the urban plume and show rapid venting and limited recirculation during MILAGRO. Lagrangian impacts were identified at the campaign supersites, and age spectra of the pollutants evaluated at those same sites. The evaluation presented in the paper show that mesoscale meteorological simulations are of sufficient accuracy to be useful for MILAGRO data analysis.

Special issue
Final-revised paper