Papers by Nilton Évora do Rosário
Revista Brasileira de Ciências Ambientais (Online), 2020
A poluição atmosférica gerada pelas atividades antrópicas afeta tanto o equilíbrio climático quan... more A poluição atmosférica gerada pelas atividades antrópicas afeta tanto o equilíbrio climático quanto a qualidade do ar. O Material Particulado (MP) é reconhecidamente o poluente atmosférico com maior impacto na saúde humana. No estado de São Paulo, as principais fontes de MP são as emissões veiculares, nas áreas urbanas, e a queima de biomassa, nas áreas rurais. Com o objetivo de mitigar a poluição nas áreas rurais, em 2007 foi assinado o protocolo agroambiental entre o estado de São Paulo e o setor sucroalcooleiro, o qualtrata da redução e da eliminação gradual do uso da queima como prática de colheita de cana até 2017. A análise da tendência nos níveis dos poluentes atmosféricos no estado é fundamental para a avaliação dos resultados do protocolo. Entretanto, apesar de apresentar a maior rede de monitoramentode qualidade do ar no Brasil, São Paulo não tem monitoramento da poluição atmosférica na maioria dos seus municípios. Nesse contexto, visando avaliar o impacto do protocolo agr...
Applied Optics, 2008
Multifilter rotating shadowband radiometer (MFRSR) calibration values for aerosol optical depth (... more Multifilter rotating shadowband radiometer (MFRSR) calibration values for aerosol optical depth (AOD) retrievals were determined by means of the general method formulated by Forgan [Appl. Opt. 33, 4841 (1994)] at a polluted urban site. The obtained precision is comparable with the classical method, the Langley plot, applied on clean mountaintops distant of pollution sources. The AOD retrieved over São Paulo City with both calibration procedures is compared with the Aerosol Robotic Network data. The observed results are similar, and, except for the shortest wavelength (415 nm), the MFRSR's AOD is systematically overestimated by ∼0:03.
Changes in solar radiation quality reaching the surface due to biomass burning aerosol particles in the Amazon Basin
Atmospheric Chemistry and Physics Discussions, 2019
In vegetation canopies with complex architectures, diffuse solar radiation can enhance carbon ass... more In vegetation canopies with complex architectures, diffuse solar radiation can enhance carbon assimilation through photosynthesis because isotropic light is able to reach deeper layers of the canopy. Although this effect has been studied in the past decade, the mechanisms and impacts of this enhancement over South America remain poorly understood. Over the Amazon deforestation arch large amounts of aerosols are released into the atmosphere due to biomass burning, which provides an ideal scenario for further investigation of this phenomenon in the presence of canopies with complex architecture. In this paper, the relation of aerosol optical depth and surface fluxes of mass and energy are evaluated over three study sites with Artificial Neural Networks and radiative transfer modeling. Results indicate a significant effect of the aerosol on flux of carbon dioxide between the vegetation and the atmosphere, as well as on energy exchange, including that surface fluxes are
Journal of Geophysical Research: Atmospheres, 2017
We analyzed the variability of downward solar irradiance reaching the surface at São Paulo city, ... more We analyzed the variability of downward solar irradiance reaching the surface at São Paulo city, Brazil, and estimated the climatological aerosol and cloud radiative effects. Eleven years of irradiance were analyzed, from 2005 to 2015. To distinguish the aerosol from the cloud effect, the radiative transfer code LibRadtran was used to calculate downward solar irradiance. Two runs were performed, one considering only ozone and water vapor daily variability, with AOD set to zero and the second allowing the three variables to change, according to mean climatological values. The difference of the 24 h mean irradiance calculated with and without aerosol resulted in the shortwave aerosol direct radiative effect, while the difference between the measured and calculated, including the aerosol, represented the cloud effect. Results showed that, climatologically, clouds can be 4 times more effective than aerosols. The cloud shortwave radiative effect presented a maximum reduction of about À170 W m À2 in January and a minimum in July, of À37 W m À2. The aerosol direct radiative effect was maximum in spring, when the transport of smoke from the Amazon and central parts of South America is frequent toward São Paulo. Around mid-September, the 24 h radiative effect due to aerosol only was estimated to be À50 W m À2. Throughout the rest of the year, the mean aerosol effect was around À20 W m À2 and was attributed to local urban sources. The effect of the cloud fraction on the cloud modification factor, defined as the ratio of all-sky irradiation to cloudless sky irradiation, showed dependence on the cloud height. Low clouds presented the highest impact while the presence of high clouds only almost did not affect solar transmittance, even in overcast conditions. Briefly, the SPMA climate is characterized by a dry season during the Southern Hemisphere wintertime (from June to August), while the wet season is observed in the summer months [Ferreira et al., 2013; Silva Dias et al., 2013]. SPMA precipitation regime is changing with extreme events becoming more YAMASOE ET AL.
Environmental monitoring and assessment, 2016
The air quality in the Metropolitan Area of São Paulo (MASP) is primarily determined by the local... more The air quality in the Metropolitan Area of São Paulo (MASP) is primarily determined by the local pollution source contribution, mainly the vehicular fleet, but there is a concern about the role of remote sources to the fine mode particles (PM2.5) concentration and composition. One of the most important remote sources of atmospheric aerosol is the biomass burning emissions from São Paulo state's inland and from the central and north portions of Brazil. This study presents a synergy of different measurements of atmospheric aerosol chemistry and optical properties in the MASP in order to show how they can be used as a tool to identify particles from local and remote sources. For the clear identification of the local and remote source contribution, aerosol properties measurements at surface level were combined with vertical profiles information. Over 15 days in the austral winter of 2012, particulate matter (PM) was collected using a cascade impactor and a Partisol sampler in São P...
Changes in solar radiation partitioning reaching the surface due to biomass burning aerosol particles in the Amazon Basin
AIP Conference Proceedings, 2009
In this paper, results from the partition of downward surface solar radiation between direct and ... more In this paper, results from the partition of downward surface solar radiation between direct and diffuse components under distinct aerosol loadings will be presented. The field experiment was conducted during 2007 dry season in the Reserva Biolo´gica do Jaru, located in the Southwestern portion of the Amazon Basin (−10.145°,−61.908°), in a region with tropical rainforest vegetation. A Multi-Filter Rotating Shadow-band Radiometer (MFRSR) was used to measure global and diffuse components of solar radiation in narrow bands (centered at 415, 670, 870 and 1036 nm) as well as broadband (from about 350 to 1100 nm) spectral regions. Due to biomass burning emissions, high values of aerosol optical depth were observed (accompanying paper by Rosario &etal;, 2008). Consequently, a significant increase in diffuse solar irradiance was also observed. For example, at channel around 670 nm, the diffuse fraction corresponded to about 80%, even at noon, for aerosol optical depth of about 2 at the same wavelength, which is expected to be about 20% at this time of the day in clean conditions. For clean days, diffuse fraction can reach maximum about 35% during early morning or late afternoon. For broadband irradiance, 70% of radiation is diffuse when AOD is about 2 around noon and would be about 15–30% for low AOD values.
This a preprint and has not been peer reviewed. Data may be preliminary.
Revista Brasileira de Climatologia
Neste estudo foram identificados os eventos climáticos secos e úmidos ocorridos no ABC Paulista (... more Neste estudo foram identificados os eventos climáticos secos e úmidos ocorridos no ABC Paulista (Santo André, São Bernardo do Campo, São Caetano do Sul, Diadema, Mauá, Rio Grande da Serra e Ribeirão Pires), uma região de grande importância hídrica, econômica e industrial no Estado de São Paulo, no período de 2000 a 2020. Para tanto, foram utilizados dados mensais de precipitação estimados pelo algoritmo IMERG aplicado às medidas da constelação de satélites da GPM, e a técnica do Índice de Precipitação Padronizada (SPI), considerando as escalas temporais de acumulação de 1, 3, 6 e 12 meses. Para todas as escalas do SPI, foram registrados 45 eventos secos (SPI-1: 25, SPI-3: 13, SPI-6: 6 e SPI-12: 1) e 50 eventos úmidos (SPI-1: 27, SPI-3:15, SPI-6: 6 e SPI-12: 2) no ABC Paulista durante o período de estudo. Utilizando o teste z para o nível de significância de 5%, as condições úmidas predominaram na primeira década (2000-2010) no SPI-1, enquanto as condições de seca foram dominantes ...
ABC Paulista is home to the Rio Grande reservoir, one of the main water supply systems for the Me... more ABC Paulista is home to the Rio Grande reservoir, one of the main water supply systems for the Metropolitan Region of São Paulo (RMSP), belonging to the Billings Dam. Comprising seven municipalities, located southeast of the RMSP, and considered a region of great social and environmental vulnerability. The changes in global climate in recent years have contributed to a greater occurrence of extreme weather events on a regional scale, especially in regions sensitive to the effects of climatic events of greater magnitude. The Standardized Precipitation Index (SPI) allows the identification of climatic events through precipitation data at different accumulation scales. The objective of this work is to analyze the variations of the level of the Rio Grande reservoir in the face of wet and dry climatic events identified through SPI-12 (annual accumulation scale) in the ABC Paulista region in the period 2000-2020. The precipitation data were extracted from the GPM/IMERG and the level (m) o...
COVID-19 mortality rates in South America related to environmental factors
International Journal of Environmental Studies, 2022
Revista Brasileira de Meteorologia, 2016
Resumo Este trabalho possui dois objetivos principais, o primeiro é apresentar uma descrição de c... more Resumo Este trabalho possui dois objetivos principais, o primeiro é apresentar uma descrição de como o modelo atmosférico BRAMS foi estruturado com o intuito de capacitá-lo a simular a emissão, dispersão e sedimentação de cinzas vulcânicas; o segundo é fazer uma análise de sensibilidade com relação a diversas configurações do modelo, com o intuito de obter uma configuração adequada para prever a concentração de cinzas vulcânicas após eventos eruptivos. Avaliando os resultados do modelo com dados observados, principalmente com relação ao satélite CALIPSO, concluiu-se que o modelo BRAMS foi capaz de simular e prever com relativa precisão a posição e concentração das cinzas vulcânicas na atmosfera.
Aerosol Optical Depth and Ångström Coefficient retrievals over the Amazon Forest during 2007 biomass burning season
An intensive measurement campaign aiming to study Photosynthetically Active Radiation profiles in... more An intensive measurement campaign aiming to study Photosynthetically Active Radiation profiles inside the canopy at the Amazon Forest took place during 2007 biomass burning season, from 22 August to 30 October. During this period, aerosol optical properties were monitored using distinct radiometers: a Multi-Filter Rotating Shadowband Radiometer (MFRSR), the AERONET sunphotometer, a handheld Microtops sunphotometer and Moderate Imaging Spectrometer (MODIS)
Fifty-six years (1961-2016) of daily surface downward solar irradiation, sunshine duration, diurn... more Fifty-six years (1961-2016) of daily surface downward solar irradiation, sunshine duration, diurnal temperature range and the fraction of the sky covered by clouds in the city of São Paulo, Brazil, were analyzed. The main purpose was to contribute to the characterization and understanding of the dimming and brightening effects on solar global radiation in this part of South America. As observed in most of the previous studies worldwide, in this study, during the period between 1961 up to the early 1980's, more specifically up to 1983, a negative trend in surface solar irradiation was detected in São Paulo, characterizing the occurrence of a dimming effect. A similar behavior, a negative trend, was also observed for sunshine duration and the diurnal temperature range, the three variables in opposition to the trend in the sky cover fraction. However, a brightening effect, as observed in western industrialized countries in more recent years, was not observed. Instead, for surface downward irradiation, the negative trend persisted and still in consonance to the cloud cover fraction increasing trend. The trends for sunshine duration and the diurnal temperature range, by contrast, changed signal. Some possible causes for the discrepancy were discussed, such as the frequency of fog occurrence, urban heat island effects, aerosol changes and greenhouse gas concentration increase. Future studies on aerosol effect are encouraged, particularly with higher temporal resolution as well as modeling studies, to better analyze the contribution of each possible causes.
Discrepancies between measured and modeled solar irradiance at the surface: the role of variability of aerosol intensive optical properties
The 2020 biomass burning season in Brazil was marked by an unprecedented amount of fire counts ac... more The 2020 biomass burning season in Brazil was marked by an unprecedented amount of fire counts across the Pantanal biome, which led to high levels of air pollution within the biome and downwind areas. Large amount of fire counts was also detected in the Amazon Forest during 2020 compared with the recent years. However, the contribution of Pantanal fire emissions to the regional smoke plume was speculated to rival the contribution of fire emissions from Amazon. Aiming to contextualise the 2020 biomass burning season focusing on the unprecedented role of Pantanal, the present study's main goal is to analyse the recent biomass burning seasons in Brazil looking at the fire counts, the regional smoke plume and its impact on surface solar radiation (SSR). The focus is on the biomes most affected by the recent biomass burning events, Amazon forest, Cerrado and especially Pantanal. To characterise the regional smoke plume we analysed aerosol optical depth, single scattering albedo and its impact on the solar radiation reaching the surface. The influence of interannual variability of the wind at 850 hPa on the transport of the regional smoke plumes was also explored. In 2020, the regional smoke plume covered an area well above 6 million km2, the largest area in the last six years, but equivalent to the observed in a more remote past, as in 2007 and 2010. However, from the point of view of Pantanal, 2020 was an unprecedented year, not due to the amount of smoke over the biome, but regarding the biome contribution to the regional smoke plume. The number of fire counts was 3.4 times higher than the mean value considering the period from 2003 to 2020. The entire biome was continuously covered by a thick smoke layer from September to October, which resulted in a monthly mean deficit of surface solar radiation up to 300 Wm-2. Additionally, the 2020 regional smoke plume presented higher optical absorption when compared with the recent years plumes, which could be related to the Pantanal larger fire emission. However, current knowledge on optical and radiative properties of smoke aerosols from Pantanal is limited compared to the one resultant from Amazon and Cerrado fire emissions, which prevent a definitive conclusion.
A poluição do ar é um dos principais problemas enfrentados em regiões urbanas, e sua percepção pe... more A poluição do ar é um dos principais problemas enfrentados em regiões urbanas, e sua percepção pela população é fundamental para a mitigação do problema. Este estudo analisou a percepção da poluição do ar por dois grupos de comerciários do município de Diadema: um atuante no centro da cidade, em uma via de intenso tráfego, e outro atuante na periferia (bairro). Os resultados demonstram que os entrevistados têm clara percepção da poluição do ar (90% no centro e 70% no bairro) e identificaram corretamente seu principal agente, a emissão veicular. Entretanto, a maioria dos entrevistados (65%) não se identificou como causa do problema. A percepção dos entrevistados sobre a evolução da qualidade do ar foi coerente com dados de concentração dos poluentes. Vale ressaltar a divergência encontrada entre a percepção dos comerciários e os índices oficiais de qualidade do ar. Não houve diferenças significativas entre as percepções dos comerciários do centro e do bairro. Palavras-chave: percepção ambiental; qualidade do ar; ozônio; material particulado; região metropolitana de São Paulo.
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Papers by Nilton Évora do Rosário