Articles | Volume 8, issue 24
Atmos. Chem. Phys., 8, 7353–7366, 2008

Special issue: Mexico City Metropolitan Area Field Campaign 2003...

Atmos. Chem. Phys., 8, 7353–7366, 2008

  11 Dec 2008

11 Dec 2008

Using 3DVAR data assimilation system to improve ozone simulations in the Mexico City basin

N. Bei2,1, B. de Foy1,3, W. Lei2,1, M. Zavala2,1, and L. T. Molina2,1 N. Bei et al.
  • 1Molina Center for Energy and the Environment, La Jolla, CA, USA
  • 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
  • 3Saint Louis University, Saint Louis, MO, USA

Abstract. This study investigates the improvement of ozone (O3) simulations in the Mexico City basin using a three-dimensional variational (3DVAR) data assimilation system in meteorological simulations during the MCMA-2003 field measurement campaign. Meteorological simulations from the NCAR/Penn State mesoscale model (MM5) are used to drive photochemical simulations with the Comprehensive Air Quality Model with extensions (CAMx) during a four-day episode on 13–16 April 2003. The simulated wind circulation, temperature, and humidity fields in the basin with the data assimilation are found to be more consistent with the observations than those from the reference deterministic forecast. This leads to improved simulations of plume position, peak O3 timing, and peak O3 concentrations in the photochemical model. The improvement in O3 simulations is especially strong during the daytime. The results demonstrate the importance of applying data assimilation in meteorological simulations for air quality studies in the Mexico City basin.

Final-revised paper