Jorge A. Martins

Air quality forecasting system for Southeastern Brazil

Southeastern Brazil, the most populous and developed region of the country, faces various environmental problems associated with the growth of its population in urban areas. It is the most industrialized area in the country, comprising the metropolitan areas of Sao Paulo, Rio de Janeiro, Belo Horizonte, and other major cities. Air quality is a major concern, because the reported concentrations of certain regulated pollutants, typically ozone and fine particulate, have exceeded national standards. Due to the difficulty in taking measurements over many different areas, air quality modeling is a useful tool to estimate air pollutant concentrations. For southeastern Brazil, air quality modeling has been performed mostly with the Brazilian Regional Atmospheric Modeling System with Simplified Photochemical Module and the Weather Research and Forecast with Chemistry models. One of the main objectives was to study the evolution of air quality associated with improved vehicle emission factors in urban areas, the impact of climate change on air quality, and the relationship between pollutant concentrations and health. Knowledge of mobile source emission factors has been continuously expanded by in-tunnel measurements and dynamometer protocols, which provide accurate data as inputs to photochemical air quality models. The spatial distribution of the mobile source emissions was constructed based on open access data related to the streets and traffic distribution. The mobile emission module was combined to the chemistry modeling and this implementation can be an example to be applied to other places that do not have a spatial distribution of this kind of source. Forecasts of pollutant concentrations can inform public policies, including those addressing the effects of pollutants on health of the general population, and studies of the impacts of using different fuels and implementation of emissions regulations programs.

Bacterial ice nuclei impact cloud lifetime and radiative properties and reduce atmospheric heat loss in the BRAMS simulation model

This study examines the effect of the bacterial species Pseudomonas syringae acting as ice nuclei (IN) on cloud properties to understand its impact on local radiative budget and heating rates. These bacteria may become active IN at temperatures as warm as −2 °C. Numerical simulations were developed using the Brazilian Regional Atmospheric Model System (BRAMS). To investigate the isolated effect of bacterial IN, four scenarios were created considering only homogeneous and bacterial ice nucleation, with 1, 10 and 100 IN per cubic meter of cloud volume and one with no bacteria. Moreover, two other scenarios were generated: the BRAMS default parameterization and its combination with bacterial IN. The model reproduced a strong convective cell over Sao Paulo on 3 March 2003. Results showed that bacterial IN may change cloud evolution as well as its microphysical properties, which in turn influence cloud radiative properties. For example, the reflected shortwave irradiance over an averaged domain in a scenario considering bacterial IN added to the BRAMS default parameterization was 14% lower than if bacteria were not considered. Heating rates can also be impacted, especially due to differences in cloud lifetime. Results suggest that the omission of bacterial IN in numerical models, including global cloud models, could neglect relevant ice nucleation processes that potentially influence cloud radiative properties.

South America Land Use and Land Cover Assessment and Preliminary Analysis of Their Impacts on Regional Atmospheric Modeling Studies

Data provided by two important sources of information on land use and land cover (LULC), MODIS-2009 and GLOBCOVER-2009, were analyzed for South America in order to assess differences related to their application in numerical modeling studies. Even though on a South American basis, the two databases showed a Pearson correlation coefficient above 85%, on a regional analysis, the correlation stayed within the range of 0%-100%, depending on the territorial unit analyzed. Significant differences were observed in most of the land cover classes, with only forested areas presenting a good level of agreement. In terms of territorial units, only areas in the Amazon region, where forest cover is predominant, showed significant correlation levels. Crops and urban classes presented the greatest differences between the two analyzed files. Results of meteorological simulations indicated that such observed discrepancies are able to cause strong impacts on modeling scenarios and important bias on simulated variables, being a crucial feature for weather and climate forecast and diagnostic.

Situação atual da qualidade do ar das principais cidades da América Latina

In this paper was done the compilation of Particulate Matter (PM) concentrations for the largest cities in Latin America, with over 1 million inhabitants in order to investigate the air quality situation in this region. For this study were obtained data from 28 cities of 13 countries from the World Health Organization reports (WHO), government agencies and monitoring stations. The results shows that, in most cities, the levels established by WHO guidelines, both PM10 and PM2.5, are exceeded, providing conditions that threaten the public health of citizens.

ANÁLISE DA SAZONALIDADE E DA TENDÊNCIA DE LONGO PRAZO NA VAZÃO DOS PRINCIPAIS TRIBUTÁRIOS DO RIO PARANÁ LOCALIZADOS NO SUL-SUDESTE DO BRASIL

This study analyzed streamflow series for the major left side tributaries of the Parana River in Brazil. The results suggest that there is agreement regarding the increase in the flow of the rivers analyzed, but increasing rates are not uniform and there are different trends among the rivers when monthly averages maximum and minimum streamflow are considered.

EVENTOS EXTREMOS DE PRECIPITAÇÃO NO ESTADO DO PARANÁ

Este estudo analisa o comportamento da precipitacao no Estado do Parana, atraves de metodos estatisticos para eventos extremos e ferramentas de SIG. Identificaram-se regioes mais vulneraveis a precipitacoes intensas, como o sudoeste do Estado, que apresentou chuvas intensas, recorrencia de extremos anuais e tendencia de aumento de extremos.

EFFECTS OF SIZE DISTRIBUTIONS FROM TWO DISTINCT POLLUTED ENVIRONMENTS ON DRY DEPOSITION OF ATMOSPHERIC AEROSOLS

Resumo Um modelo matematico simples foi utilizado para estudar o efeito da distribuicao de tamanho das particulas sobre a eficiencia de remocao por deposicao seca. Para esta finalidade foram utilizadas duas distribuicoes de tamanho de aerossois, tipicas de ambientes poluidos: uma distribuicao de ambiente de queimada (Amazonia) e outra de ambiente urbano (Sao Paulo). Os resultados mostraram que particulas originarias de ambiente urbano sao mais eficientemente removidas por deposicao seca do que particulas de queimada. Este comportamento esta associado ao fato de que a natureza de remocao das particulas por deposicao seca e pouco eficiente para diâmetros entre 0,1 e 1,0 mm, dominio em que se concentra a maior parte das particulas de queimada. Esse mecanismo diferencial de deposicao e o que explica o maior efeito deleterio das particulas ultra-finas no sistema respiratorio humano.

PARTICULATE MATTER CONCENTRATION FORECAST OVER THE METROPOLITAN AREA OF SÃO PAULO

Em virtude dos grandes males causados a saude pela poluicao nosgrandes centros urbanos, a utilizacao de modelos meteorologicos acopladosaos modelos quimicos, resultando em modelos de previsao da qualidade doar, tem aumentado significativamente nos ultimos anos. Exemplos dessetipo de utilizacao sao os modelos WRF-CHEM, utilizado em varios paisesdo mundo, e SPM-BRAMS, recentemente desenvolvido por pesquisadoresda Universidade de Sao Paulo e do INPE e utilizado operacionalmente nolaboratorio MASTER do IAG-USP. Embora o modelo seja utilizado para aprevisao das concentracoes dos principais poluentes monitorados na regiao, neste trabalho sao apresentadas comparacoes entre as concentracoesde material particulado fino (PM2.5) previstas e aquelas derivadas das observacoes na rede da CETESB. O PM2.5 esta relacionado aos efeitos deleteriosa saude e esta sendo estudado o estabelecimento de um padrao de qualidadedo ar para esse poluente. Alem da questao da relacao com impactosnegativos a saude, ha tambem os impactos ao clima, ja que as particulasfinas estao relacionadas com a formacao de precipitacao e extincao da radiacao.