São Paulo Aerosol Characterization Study

Abstract

The São Paulo Metropolitan area (SPMA) is characterized as having one of the worst air pollution problems in Brazil,with frequent violations of air quality standards for particulate matter. This paper presents the results of a eceptor model source apportionment study carried out to develop a quantitative database on which a control strategy could be developed. The study was conducted in four sites with distinct land uses. Fine, coarse (CP), and total suspended particles (TSP) samples were collected on Teflon and glass filters and analyzed by x-ray fluorescence XRF), ion chromatography, and thermal evolution. The sources were characterized by similar methodology. Chemical mass balance (CMB) receptor modeling indicated that carbonaceous material plays an important role in the aerosol composition; that the three major source categories contributing to the fine particles are vehicles, secondary carbon, and sulfates; and that the main contributors to CP and TSP are road dust and vehicles. All sampling sites presented the same general pattern in terms of source contribution, although this contribution varied from site to site.     

Distribution of nutrients and AOU in the Mediterranean Water (North Atlantic Ocean)

Water samples were collected in the Northeast Atlantic Ocean (33-37^° N and 11-16^° W) in May 1983, and vertical profiles of chemical and physical parameters allowed us to identify the different water masses. A significant difference in salinity and its maximum can be found at different places and depths, as a consequence of the spreading of the Mediterranean Water (MW) from the Strait of Gibraltar. The apparent oxygen utilization shows a correlation with nutrients in North Atlantic Central Water. The relative percentages of water masses were assessed in order to examine the depth of maximum influence of MW as a function of latitude and to apply this knowledge to the black scabbard fish long-line strategy. The long-line fishing depth location was adapted to the specific MW distribution of the different banks with improvements in the mean catch efficiency. The thickness of the MW prevalence layer has a pronounced decrease to the south. MW influence clearly sinks and decrease to south-west. The highest percentage of the MW was found in the Gorringe Bank area and the lowest in the Madeira area.