Publicações

The wind energy share is growing fast in Brazil and a better understanding of wind speed vertical profiles is essential for accurate power density estimates. The wind shear is highly variable in space and time, being influenced by surface layer stability. Studies concerning wind vertical profiles may have a significant contribution to the Brazilian energy sector. However, wind observational data are very scarce and most of them were acquired in automated weather stations. This work investigates the wind vertical profile data acquired at a wind mast in a semi-arid region of Brazilian Northeastern region, correlating it to stability conditions of the surface boundary layer, surface roughness and friction velocity. The results indicated that strong winds (>7 m sec−1) overcome the stability effects, allowing a better estimate of roughness length, friction velocity and exponential coefficient. In a second step, the wind speed at 50 m agl. Were estimated from wind measurements at 25 m agl. The wind estimates were compared to observations, showing that exponential and logarithmic approaches were able to simulate wind profile. The exponential approach presented the lowest BIAS for rainy season, but overestimated high wind velocities. Finally, a sensitivity analysis demonstrated how uncertainties on roughness length and exponential coefficient impacts on BIAS deviation and reduce the confidence on wind power density estimates. The results demonstrated the importance in understanding how wind vertical profile is related to atmospheric stability condition in order to get reliable values for the shear parameters from mast observations. It is still more critical if wind database is short-term and when dealing with lower wind speeds.

Recognized as one of the world’s most vital natural and cultural resources, the Amazon faces a wide variety of threats from natural resource and infrastructure development. Within this context, rigorous scientific study of the region’s complex social-ecological system is critical to inform and direct decision-making toward more sustainable environmental and social outcomes. Given the Amazon’s tightly linked social and ecological components and the scope of potential development impacts, effective study of this system requires an easily accessible resource that provides a broad and reliable data baseline. This paper brings together multiple datasets from diverse disciplines (including human health, socio-economics, environment, hydrology, and energy) to provide investigators with a variety of baseline data to explore the multiple long-term effects of infrastructure development in the Brazilian Amazon.

There has been a growing demand on energy sector for short-term predictions of energy resources to support the planning and management of electricity generation and distribution systems. The purpose of this work is establishing a methodology to produce solar irradiation forecasts for the Brazilian Northeastern region by using Weather Research and Forecasting Model (WRF) combined with a statistical post-processing method. The 24 h solar irradiance forecasts were obtained using the WRF model. In order to reduce uncertainties, a cluster analysis technique was employed to select areas presenting similar climate features. Comparison analysis between WRF model outputs and observational data were performed to evaluate the model skill in forecasting surface solar irradiance. Next, model-derived short-term solar irradiance forecasts from the WRF outputs were refined by using an artificial neural networks (ANNs) technique. The output variables of the WRF model representing the forecasted atmospheric conditions were used as predictors by ANNs, adjusted to calculate the solar radiation incident for the entire Brazilian Northeastern (NEB) (which was divided into four homogeneous regions, defined by the Ward method). The data used in this study was from rainy and dry seasons between 2009 and 2011. Several predictors were tested to adjust and simulate the ANNs. We found the best ANN architecture and a group of 10 predictors, in which a deeper analyzes were carried out, including performance evaluation for Fall and Spring of 2011 (rainy and dry season in NEB, mainly in the northern section). There was a significant improvement of the WRF model forecasts when adjusted by the ANNs, yielding lower bias and RMSE, and an increase in the correlation coefficient.

In a context of international scrutiny, important efforts are being made to preserve Brazils tropical forests. Meanwhile, the destruction of its Cerrado biome advances with increasing leaps but little controversy. Yet the damaging changes threaten life-supporting natural resources and ecosystem services that are vital for the majority of Brazilians, as well as for the continued viability of agriculture. This ancient region of considerable geological and cultural significance encapsulates all of the major environmental challenges to sustainability, and begs new responses from science and society. Fresh policies are needed to promote and integrate the importance of this biome for the nation. These include implementing systematic monitoring systems and improving the management of established ones, minimizing new clearing. Degraded areas must be restored to comply with existing Brazilian environmental laws and international commitments related to climate change, biodiversity conservation, and sustainable development. Addressing the threats to this critically important yet neglected biome requires attention to structural governance problems, including improved education and involvement of stakeholders in key decision making about the region, as well as historically informed reexamination of the countrys economic development path.

Future Earth is an evolving international research program and platform for engagement aiming to support transitions toward sustainability. This article discusses processes that led to Future Earth, highlighting its intellectual emergence. I describe how Future Earth has increased space for contributions from the social sciences and humanities despite powerful, longstanding preferences for bio-geophysical research in global environmental research communities. I argue that such preferences nevertheless are deeply embedded in scientific institutions that continue to shape environmental science agendas and, as such, constitute a formidable obstacle that needs to be recognized and countered to bolster efforts at effective societal transformation in the face of sustainability challenges. The analysis draws on two decades of observant participation in environmental research communities in the United States, Europe, Brazil, and elsewhere, including participation in the visioning process that led to Future Earth.

Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basinwide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs.

Neglecting any atmospheric feedback to precipitation, deforestation in Amazon, i.e., replacement of trees by shallow rooted short vegetation, is expected to decrease evapotranspiration (ET). Under energy-limited conditions, this process should lead to higher soil moisture and a consequent increase in river discharge. The magnitude and sign of the response of ET to deforestation depends both on land-cover change (LCC), and on climate and CO2 concentration changes in the future. Using . Neglecting any atmospheric feedback to precipitation, deforestation in Amazon, i.e., replacement of trees by shallow rooted short vegetation, is expected to decrease evapotranspiration (ET). Under energy-limited conditions, this process should lead to higher soil moisture and a consequent increase in river discharge. The magnitude and sign of the response of ET to deforestation depends both on land-cover change (LCC), and on climate and CO2 concentration changes in the future.

The purpose of this study was to evaluate the concentrations of tropospheric ozone and VOCs under the sugarcane agroindustry emissions in urban and rural areas of Araraquara, SP. The sampling was performed using active and passive air samplers during the sugarcane harvest and in the period between harvests in 2011 and 2012. Also, canisters were undertaken in 3 situations: during and after the burning of the cane plantations and in an urban area. Instrumental analysis was carried out using gas and ion chromatography. The highest VOC concentrations were found for toluene and d-limonene at the urban area and for ethene during the burning of sugarcane. Although sugarcane industry is an important emission source of ozone precursors, in this study the tropospheric ozone levels do not increased significantly under sugarcane agro-industry emissions

September 2015 was an atypical austral winter rainy month. Rainstorms were observed in Sao Paulo State, Brazil (53o W-44o W; 20o S-25o S) with catastrophic consequences. In this paper the atmospheric conditions responsible for the rainstorms that occurred on 8th September 2015 in Sao Paulo State and their social and economic consequences were analyzed. The results showed that the rainstorms affected practically the entire Sao Paulo State causing floods and threw down trees, interrupting of the traffic on the streets and affecting the system of electric energy. Rainstorms accompanied by high winds and strong divergence at 200 hPa and ascending motion were observed due to intense squall line moving over Sao Paulo State. Satellite and radar images showed strong convective activity and the heavier rainfall (around 90 mm) in the center-east sector at 20:45 UTC. Hourly data from meteorological stations showed that the wind gust and the precipitation were higher than 65 km h-1 and 10 mm, respectively in almost the entire State. In Sao Paulo city, the rainfall was the highest for September in the last 20 years. The amount of precipitation was 3% higher than the amount expected for the entire September. Since each region of inundation in Sao Paulo city causes a daily damage higher than US$ 263,000,00 a great economic harm must be expected. A co-operative project between National Institute for Space Research (INPE) institution and Energisa Power Company is in progress aimed to mitigate the effects of adverse weather conditions as in the case of the rainstorm that occurred in 8th September 2015.

O objetivo desse trabalho foi avaliar a erodibilidade de um Cambissolo existente na sub-bacia do Córrego do Yung, localizada em Juiz de Fora, mesorregião da Zona da Mata Mineira. Analisou-se o comportamento dos horizontes pedológicos B e C, e, a partir de ensaios geotécnicos, de caracterização mineralógica e de caracterização física dos materiais, foram estabelecidas correlações qualitativas com a sua erodibilidade. Assim, determinou-se a granulometria, os limites de Liquidez e Plasticidade, mineralogia (difração de raios-X), a erodibilidade (Inderbitzen) e a resistência ao cisalhamento direto. O solo foi classificado como Cambissolo Háplico Tb Distrófico latossólico. O ensaio de Inderbitzen apresentou maior perda de solo acumulado no horizonte C, em vista do menor teor de argila e ausência de estrutura, que condicionam grãos mais soltos. Também foi verificada menor resistência ao cisalhamento na condição inundada desse horizonte. Concluindo, na sub-bacia do Córrego do Yung as áreas com maior potencial de erosão são aquelas em que se expõe o horizonte C.

This study deals with the main environmental impacts and possible mitigation measures for many pipeline tracks, due to the mining of different substances in areas of interference between mining activities and mineral research and those resulting from construction and gas pipeline operation. By monitoring the identified interferences/ disturbances, it was determined that although punctual and small in number, the extraction of mineral resources in the proximity of the gas pipelines could represent risks for the security of the undertaking. In general the risks are consequence either of the use of explosives or of induced erosive processes that could lead to pipeline instability. It is necessary to block the mining activities on both sides of the pipeline tracks in order to minimize risks to the pipeline, to others, to society, and to the environment. Also, the establishment of flexible track limits could be adopted in areas adjacent to the pipelines for the exploration of some mineral deposits, thus prioritizing security preservation with a minimum of socio-environmental impacts.