First GURME Air Quality Forecasting Workshop for Latin American project, Santiago, Chile, 13-16 October, 2003 Atmospheric aerosols in Sao Paulo, Mexico City and Santiago de Chile: Optical Properties, Remote sensing and Sources Paulo Artaxo, Andrea D. A. Castanho and Carlos Pires Junior Laboratory of Atmospheric Physics, University of São Paulo, Brazil. artaxo@if.usp.br

Health Effects of air pollution in Mexico, São Paulo, Santiago and New York

The São Paulo Metropolitan Area Question: Can we do urban air pollution by satellites?

The São Paulo Metropolitan Area Geography Lat 23o 32’S Lon46o38’O Altitude 860 m Peaks with 1.200 m altitudes surrounding the city Population: 16,3 millions inhabitants Climate Dry winters, rainy summers Frequent thermal inversions at very low altitudes with high subsidence Industry Most developed region in Latin America Represents 18% of the Brazilian production Vehicles About 6 millions vehicles with high emission factors. Old buses, many diesel trucks

Estimates of emissions from the main air pollution sources in São Paulo, 2002 1 - Gasolina C: gasolina contendo 22% de álcool anidro e 700ppm de enxofre (massa) 2 - Diesel: tipo metropolitano com 1100ppm de enxofre (massa) 3 - Emissão composta para o ar (partículas) e para o solo (impregnação) 4 - MP refere-se ao total de material particulado, sendo que as partículas inaláveis são uma fração deste total 5 - Ano de consolidação do inventário: 1990 6 - Ano de consolidação do inventário: 1998 7 - Estas indústrias fazem parte da curva A e B que representam mais de 90% das emissões totais CO: monóxido de carbono HC: hidrocarbonetos totais NOX: óxidos de nitrogênio SOX: óxidos de enxofre MP: material particulado

São Paulo 2002 Relative pollutant emissions for each source type – CETESB Most of the emissions of CO and HC are related to light vehicles, while heavy vehicles account for most of the NOx emissions. Industry is mostly responsible for the bigger portion of SO2 emissions. Heavy vehicles, aerosols, and resuspension account for most of the PM10. NOx PM10 CO HC SO2 Light vehicles Industry Heavy vehicles Ressuspension Secondary aerosols

Wintertime Fine and Coarse Mode aerosol 1997 Air Quality Standard Cold Fronts Arrivals

PM10 diurnal cycle in São Paulo

Diurnal Cycle of Black carbon - Winter 1997

Ratio of Back to Organic Carbon – São Paulo Winter 1997

Diurnal Cycle of BC/PM10 and OC/PM10 São Paulo - Winter 1997

Diurnal Cycle of CO, NOx, SO2 and PM10 wintertime São Paulo

Summer and wintertime São Paulo fine mode aerosol composition

Summer and wintertime São Paulo coarse mode aerosol composition

Fine mode aerosol source apportionment in São Paulo Winter 1997 Summer 1998

Coarse mode aerosol source apportionment in São Paulo Winter 1997 Summer 1998

Source Profile for soil dust in São Paulo and Santiago PM10

Source Profile for vehicular emissions in São Paulo and Santiago

Aerosol size distribution Santiago Pudahuel 2003

taerosol tRayleigh+ tOzone t= taerosol + trayleigh + tozone Aerosol Optical Thicknesss I l = Io l exp [–t.AM] t= taerosol + trayleigh + tozone CIMEL Iol t taerosol Aerosol Layer tRayleigh+ tOzone I l

AERONET (AErosol RObotic NETwork) ~200 sites 2003 Several wavelenghts 340, 440, 500, 675, 870, 936 Iniciou basicamente com 20 sites a 10 anos atras 1993 nos EUA e no Brasil (Amazônia)

Biomass Burning coves millions of km2 Figure from Saulo Freitas and Karla Longo

Figure from Saulo Freitas and Karla Longo

MODIS Images of South America

Low aerosol distribution situation

Aerosols acumulating in Bolivia, Paraguay, Argentina and Brazil

AOT 550 nm – Dia 02 220- ilustrativo

Low Troposphere and Long Distance Transport of PM2 Low Troposphere and Long Distance Transport of PM2.5 and CO – Andes Low Level Jets 720mbar

Suppression of low cloud formation by aerosols in Amazonia Cloud fraction as function of aerosol optical depth (OD). The cloud fraction decreases almost linearly with increasing OD. The red and blue curves denote the average of east and west areas, respectively. On average, the cloud fraction decreases to less than 1/8 of the cloud fraction in clean conditions when OD = 1. The shaded area represents the relative area covered by the respective OD, with the integral of this curve equal to one, representing the total Amazon basin. (from Ilya and Kaufman, 2003)

Amazonia Average aerosol forcing clear sky INDOEX average aerosol forcing clear sky Top: - 10 w/m² Top: - 7±1 w/m² Atmosphere: + 28 w/m² Atmosphere: + 16±2 w/m² Surface: - 38 w/m² Surface: - 23±2 w/m² Conditions: surface: forest vegetation AOT (=0.95 at 500nm); 24 hour average 7 years (93-95, 99-02 dry season Aug-Oct) Conditions: surface: ocean AOT (=0.3 at 630 nm); 24 hour average Jan-Mar 99

Aerosol Radiative Effects on the Atmosphere Cooling of up to 3 degrees Heating of up to 2 degrees Source: Saulo Freitas and Karla Longo

Aerosol Particles Radiative Effects on the Surface Temperature Aug 25 2002 16:00Z Source: Saulo Freitas and Karla Longo

Some key points The use of combined ground based, remote sensing from space and sun-photometers is a new very powerful tool. Aerosol products with MODIS with 1km resolution is a reality, and MISR with 250 meters will be available very soon. Ozone, formaldehyde and CO are already feasible with some effort and compromises. Impact of aerosols on the hydrological cycle and in the radiation budget is very poorly understood and more effort is critical in this area. High resolution mesoscale models are mature technology, that can be run in inexpensive Linux clusters in real time. A coherent and integrated approach for Latin American air pollution studies is feasible with low resources.