In the Metropolitan Area of Sao Paulo, air quality monitoring network often register ozone concentration values higher than those established by Brazilian legislation. In some occasions, weather conditions favorable to ozone formation allow the occurrence of high concentration values for several consecutive days in the area. The influence of meteorological conditions on the air pollution episode registered between February 24 and March 05, 2003 was assessed through numerical simulations with the SPM-BRAMS model. Observational studies show that the occurrence of calm winds, especially during the night and morning, favor the formation of high ozone concentration values over the region. The penetration time and the influence of the sea breeze are essential for the transport of ozone and its precursors. These conditions were well simulated by the model. For the most critical days, when several monitoring stations recorded the occurrence of violations to the ozone National Air Quality Standard, the model simulated properly the atmospheric conditions needed for the maintenance of high ozone concentration values, without any artificial procedure during the integrations.
Atmospheric Pollution; Urban Problems; SPM-BRAMS
