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| Author(s): |
Andrea Dardes de Almeida Castanho
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Física (IF/SBI) |
| Defense date: | 2005-04-18 |
| Examining board members: |
Paulo Eduardo Artaxo Netto;
Maria de Fatima Andrade;
Juan Carlos Ceballos;
Pedro Leite da Silva Dias;
Mikiya Muramatsu
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| Advisor: | Paulo Eduardo Artaxo Netto |
| Abstract | |
Urban air pollution is a public concern in all megacities around the world. Aerosol particles are active participants in the atmospheric energy budget, cloud properties, atmospheric chemistry and have adverse effects on human health. The spatial extension and the high growth rate of the megacities show the need of the use of remote sensing technologies on urban air pollution monitoring. Optical properties of São Paulo aerosol particles were analyzed using global sun photometer measurements from the AERONET (Aerosol Robotic Network) operated by NASA. A new methodology was developed to retrieve aerosol optical thickness in 1x1 km resolution over São Paulo metropolitan area from satelites measurements. Five aerosol optical models representative of the region were defined as a function of the single scattering albedo. The single scattering albedo in 550 nm varied from 0,83 to 0,93 in the models. Radiances were used from MODIS (Moderate-Resolution Imaging Spectroradiometer) sensor on Terra and Aqua NASA platforms. Sensitivities studies have shown the importance of the single scattering albedo, assymmetry parameter, surface reflectance, water vapor and other properties in the aerosol optical thickness retrieval from space. The developed algorithm uses the critical reflectance aerosol property, that is obtainable from the sensor measurements, to identify the aerosol model to be used. This procedure allow a more precise and dynamic definition of the aerosol model, reducing the uncertainties in the aerosol optical thickness retrieved from the MODIS sensor. Validation results have shown a significant improvement in a comparison between aerosol optical thickness obtained from MODIS and from surface radiometers measurements. Aerosol optical thickness images with 1x1 km resolution were obtained with this methodology and shows that the increase in the resolution of the aerosol optical thickness provides a more effective monitoring of the aerosol distribution in São Paulo. The case studies have shown the potentiality of this methodology to identify an adequate aerosol model, for both local aerosol pollution and in the long distance transport of pollutants. The models and procedures developed in this work can be applied in other urban regions with the appropriate validation. The presented product can be operational and used as routine measurement by environmental agencies in megacities, as an example, for CETESB in São Paulo, as a complementary tool to the regular ground based particulate matter monitoring. (AU) | |
| FAPESP's process: | 99/12493-2 - Characterization of physical and chemical properties of the aerosol particles for the metropolitan region of São Paulo |
| Grantee: | Andréa Dardes de Almeida Castanho |
| Support Opportunities: | Scholarships in Brazil - Doctorate |