Using a 3-D Air Quality Model to Assess Ground-LevelOzone Production in S?o Paulo

摘要

In a joint study carried out by PETROBRAS R&D Center (CENPES) and S?o Paulo UniversityAtmospheric Sciences Department (USP-IAG), tropospheric ozone formation and transport arebeing currently assessed in the Metropolitan Area of S?o Paulo (MASP) using the threedimensionalEulerian photochemical model CIT, developed by Carnegie Mellon University(CMU) and California Institute of Technology (Caltech). Given the limitations of the availableinformation regarding updated and “real world” atmospheric emissions, both on the side of theindustrial facilities located within the city airshed and also on the current running fleet in S?oPaulo, the base case to run CIT is built resorting to a step-by-step approach. The preliminarybase case targets to portray MASP air quality status with emphasis on ozone, fitting the largestdata base available for S?o Paulo, which refers to 2000. In that initial version the criteriapollutants (NO2, NO, CO, SO2 and ozone) ambient concentrations were forecasted and comparedto the official air quality records (CETESB), thus covering the period from 22 to 24 August2000, in which measured ozone concentrations exceeded the 1 hour NAAQS (80 ppb). Anoverall good fit of the model output as compared to the ambient monitoring data was reached.The next step is to add on the available information both on meteorological parameters, as wellas emissions and air quality data, to build the more recent base-case for 2003. In that updatedversion, atmospheric characterization data regarding VOC speciation campaigns, carried out inMASP by CENPES and international environmental consultants (DGA, USA) in 2003/2004, arebeing incorporated, connecting kinetic modeling targeting O3 forecast to the current urban airquality status, described on the basis of its reactive precursors.