Basin-scale wind transport during the MILAGRO field campaign and comparison to climatology using cluster analysis B. de Foy1,2, J. D. Fast3, S. J. Paech4, D. Phillips4, J. T. Walters4, R. L. Coulter5, T. J. Martin5, M. S. Pekour3, W. J. Shaw3, P. P. Kastendeuch6, N. A. Marley7, A. Retama8, and L. T. Molina1,9 1Molina Center for Energy and the Environment, CA, USA 2Department of Earth and Atmospheric Sciences, Saint Louis University, USA 3Pacific Northwest National Laboratory, Richland, WA, USA 4National Space Science and Technology Center, University of Alabama in Huntsville, AL, USA 5Argonne National Laboratory, IL, USA 6Centre de Géochimie de la Surface, Université Louis Pasteur, Strasbourg, France 7Department of Chemistry, University of Arkansas at Little Rock, AK, USA 8Secretaría del Medio Ambiente, Gobierno del Distrito Federal, México 9Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, USA
Abstract. The MILAGRO field campaign was a multi-agency international
collaborative project to evaluate the regional impacts of the
Mexico City air pollution plume as a means of understanding
urban impacts on the global climate.
Mexico City lies on an elevated plateau with mountains on
three sides and has complex mountain and surface-driven
This paper asks what the wind transport was in the basin
during the field campaign and how representative it was of
Surface meteorology and air quality data, radiosondes and
radar wind profiler data were collected at sites in the
basin and its vicinity.
Cluster analysis was used to identify the dominant
wind patterns both during the campaign and within the past
10 years of operational data from the warm dry season.
Our analysis shows that March 2006 was representative of
typical flow patterns experienced in the basin.
Six episode types were identified for the basin-scale
circulation providing a way of interpreting atmospheric chemistry and
particulate data collected during the campaign.
Decoupling between surface winds and those aloft had a strong influence
in leading to convection and poor air quality episodes.
Hourly characterisation of wind circulation during the MILAGRO,
MCMA-2003 and IMADA field campaigns enables the comparisons of
similar air pollution episodes and the evaluation of the
impact of wind transport
on measurements of the atmospheric chemistry taking place in the basin.
Citation: de Foy, B., Fast, J. D., Paech, S. J., Phillips, D., Walters, J. T., Coulter, R. L., Martin, T. J., Pekour, M. S., Shaw, W. J., Kastendeuch, P. P., Marley, N. A., Retama, A., and Molina, L. T.: Basin-scale wind transport during the MILAGRO field campaign and comparison to climatology using cluster analysis, Atmos. Chem. Phys., 8, 1209-1224, doi:10.5194/acp-8-1209-2008, 2008.