HR: 17:48h
AN: A24A-09    [Abstracts]
TI: Analysis of Potential Source Areas in MCMA-2003 using Concentration Fields Based on Modeled Back-trajectories
AU: * de Foy, B
EM: foy@mit.edu
AF: Departments of Earth, Atmospheric and Planetary Sciences and of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: Molina, L T
AF: Departments of Earth, Atmospheric and Planetary Sciences and of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: Molina, M J
AF: Departments of Earth, Atmospheric and Planetary Sciences and of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: Salcedo, D
AF: Universidad Aut¢noma del Estado de Morelos, Av. Universidad #1001, Cuernavaca, 62210 Mexico
AU: Dzepina, K
AF: University of Colorado-Boulder, Department of Chemistry & Biochemistry; and CIRES, UCB 216, Boulder, CO 80309 United States
AU: Jimenez, J
AF: University of Colorado-Boulder, Department of Chemistry & Biochemistry; and CIRES, UCB 216, Boulder, CO 80309 United States
AB: A meso-scale meteorological model (MM5) was used to forecast winds inside the Mexico City basin during the MCMA-2003 field campaign at high resolution. Backward and forward trajectories were calculated using the model FLEXTRA for an ensemble of particles arriving at the campaign supersite located at the National Center for Environmental Research and Training (CENICA) during the five-week time period. Residence time analysis showed short ventilation times inside the basin and only limited recirculation on certain days. This suggests that multi-day accumulation is not the main cause of high pollutant levels inside the basin. Backward trajectories were used to obtain concentration fields so as to identify possible source regions of measured pollutants. In order to verify the method this was applied to carbon monoxide, for which the emission sources are well characterized, at different monitoring sites. The method was then applied to sulfur dioxide and aerosol mass spectrometer measurements. This showed the importance of long-range transport for certain industrial sources and the predominance of emissions from the city center. Biogenic, volcanic and crustal emissions are also evaluated with their possible impact on pollutant levels in the city.
DE: 3329 Mesoscale meteorology
DE: 0322 Constituent sources and sinks
DE: 0345 Pollution--urban and regional (0305)
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting