Publicações

Historically, during periods of extreme drought, food security in the drylands of the semiarid region of Northeast Brazil (NEB) is under severe risk due to agricultural collapse. The drought that started in 2012 continues to highlight the vulnerability of this region, and arid conditions have been detected during the last years mainly in the central semiarid region, covering almost 2% of the NEB. Climate projections show an increase in the area under water stress condition, covering 49% and 54% of the NEB region by 2700 and 2100, respectively, with a higher likelihood with warming above 4 degrees C. The projections of vegetative stress conditions derived from the empirical model for Vegetation Health Index (VHI) are consistent with projections from vegetation models, where semi-desert types typical of arid conditions would replace the current semiarid bushland vegetation (“caatinga”) by 2100. Due to the impacts of the 2012-2017 drought, public policies have been implemented to reduce social and economic vulnerability for small farmers but are not enough as poor population continues to be affected. In the long term, to make the semiarid less vulnerable to drought, strengthened integrated water resources management and a proactive drought policy are needed to restructure the economy. Integrating drought monitoring and seasonal climate forecasting provides means of assessing impacts of climate variability and change, leading to disaster risk reduction through early warning. Lastly, there is an urgent need for integrated assessments because the possibility that under permanent drought conditions with warming above 4 degrees C, arid conditions would prevail in NEB since 2060.

Several studies show the effects of lake breezes on cloudiness over natural lakes and large rivers, but only few contain information regarding large flooded areas of hydroelectric dams. Most Brazilian hydropower plants have large water reservoirs that may induce significant changes in the local environment. In this work, we describe the prevailing breeze mechanism in a Brazilian tropical hydropower reservoir to assess its impacts on local cloudiness and incoming surface solar irradiation. GOES-16 visible imagery, ISCCP database products, and ground measurement sites operated by INMET and LABREN/INPE provided data for the statistical analysis. We evaluate the cloudiness frequency assuming two distinct perspectives: spatial distribution by comparing cloudiness over the water surface and areas nearby its shores, and time analysis by comparing cloudiness prior and after reservoir completion. We also evaluated the solar irradiance enhancement over the water surface compared to the border and land areas surrounding the hydropower reservoir. The results pointed out daily average cloudiness increases moving away from the reservoir in any of the four cardinal directions. When looking at the afternoon-only cloudiness (14 h to 16 h local time), 4% fewer clouds were observed over the flooded area during summer (DJF). This difference reaches 8% during autumn (MAM) and spring (SON). Consequently, the irradiance enhancement at the water surface compared to external areas was around 1.75% for daily average and 4.59% for the afternoon-only average. Our results suggest that floating solar PV power plants in hydropower reservoirs can be an excellent option to integrate both renewable energy resources into a hybrid power generation due to the high solar irradiance in Brazilian territory combined with the prevailing breeze mechanism in large tropical water reservoirs.

O conhecimento e o desenvolvimento científicos e tecnológicos promovidos por Universidades e Instituições de Pesquisa são essenciais para o Brasil, bem como sua difusão à população, de modo que a sociedade tenha consciência de sua importância e apoie novas produções no âmbito da ciência e da tecnologia. Diante desse contexto, o Projeto Educação Extensão Educacional: Um Projeto de Difusão do Conhecimento Científico foi iniciado em 2017 pelo Centro de Ciência do Sistema Terrestre (CCST) do Instituto Nacional de Pesquisas Espaciais (INPE), com o objetivo de promover ao sistema educacional e à sociedade brasileira palestras sobre temas ambientais inerentes aos trabalhos do Instituto. Assim, esta Iniciação Científica teve como objetivo principal contribuir para o avanço do Projeto por meio de: levantamento dos temas e trabalhos desenvolvidos pelo INPE; pesquisas acadêmicas em bancos de dados científicos sobre os temas a serem difundidos; consultas no banco de dados do Projeto aos temas, número de palestras realizadas e número de participantes alcançados; e análise dos dados. Desde o início de sua atuação, em 2017, o Projeto promoveu um total de 289 palestras didáticas relacionadas aos seguintes temas científico ambientais: Biomas do Brasil; Desastres Naturais e Escorregamentos de Terra; Desmatamento; Difusão do Conhecimento Científico; Eucalipto; Fitorremediação; Geografia da Malária no Brasil; Geotecnologias; Hidrologia e Mudanças do Uso e Cobertura da Terra; Meteorologia Básica; Mudanças Ambientais Globais; Oceanografia; Padrões de Urbanização e Gestão das Cidades; Pegada Ecológica; Qualidade do Ar; Queimadas; Recuperação de Nascentes; e Reflorestamento. Essas informações, bem como outros dados relevantes ao Projeto, são armazenadas e constantemente atualizadas em um banco de dados criado em 2018. A qualidade das palestras foi avaliada em 2019 através de pesquisa eletrônica realizada com os participantes, cujos resultados foram positivos. Dentre os temas citados, o mais abordado tanto em 2017 quanto em 2019 foi Biomas do Brasil. Em 2018, predominaram as palestras sobre Desastres Naturais e Escorregamentos de Terra. Os temas Desmatamento, Qualidade do Ar, Queimadas, Recuperação de Nascentes e Reflorestamento foram frequentemente difundidos durante todos os anos do Projeto. Ademais, em 2019, foram promovidos os cursos: Uso de geotecnologias em estudos ambientais, realizado na Escola de Engenharia de Lorena (EEL/USP); e Técnicas de preservação e recuperação ambiental: um projeto de revitalização do espaço escolar, na Escola Estadual Maria Izabel Fontoura, localizada no município de Cachoeira Paulista. Através dessas ações, foi alcançado um total de 11.399 pessoas, incluindo Alunos (Discentes) e Professores (Docentes) dos ensinos fundamental e médio de escolas públicas e de Universidades. Estão em desenvolvimento novos temas, como Biorremediação de solos contaminados, a serem palestrados no futuro com a sequência do Projeto.

The conversion of primary forest (PF) to other types of land cover, such as pasture and agriculture, in Amazonia, affects regional carbon and water balances, significantly contributing to increased carbon emissions and reduced evapotranspiration. However, secondary forest (SF) growth, resulting from the abandonment of low-productivity pasture areas, offers a potential alternative to counterbalance the effects of deforestation on carbon release to the atmosphere and evapotranspiration reduction. In this work, we present four years of eddy flux measurements of a SF that is approximately 20 years old, located in Central Amazonia, and we compare these measurements with those of a PF in the same region, analyzing daily and seasonal variations in evapotranspiration, gross primary productivity of carbon and water use efficiency. On average, evapotranspiration is 20% higher in the SF (3.6 mm day−1) than in the PF (3.1 mm day−1), while gross primary productivity is only 5% higher in the SF (8.1 gC m−2 day−1) than in the PF (7.8 gC m−2 day−1). Despite robust evidence of higher evapotranspiration and gross primary productivity in SF, the estimated uncertainty range of WUE is large to reach definite conclusions about the differences on carbon gain per water loss between the sites. Nonetheless, the significantly higher evapotranspiration and gross primary productivity of SF may counterbalance both water and C losses from deforestation and has important implications for regional budgets.

The Brazilian Earth System Model (BESM-OA2.5), while simulating the historical period proposed by the fifth phase of the Coupled Model Intercomparison Project (CMIP5), detects an increasing trend in the sea surface height (SSH) on the southern hemisphere oceans relative to that of the pre-industrial era. The increasing trend is accentuated in the CMIP5 RCP4.5 and RCP8.5 future scenarios with higher concentrations of greenhouse gases in the atmosphere. This study sheds light on the sources of such trends in these regions. The results suggest an association with the thermal expansion of the oceans in the upper 700 m due to a gradual warming inflicted by those future scenarios. BESM-OA2.5 presents a surface height increase of 0.11 m in the historical period of 18502005. Concerning future projections, BESM-OA2.5 projects SSH increases of 0.14 and 0.23 m (relative to the historical 2005 value) for RCP4.5 and RCP8.5, respectively, by the end of 2100. These increases are predominantly in a band of latitude within 35608S in the Atlantic and Indian oceans. The reproducibility of the trend signal detected in the BESM-OA2.5 simulations is confirmed by the results of three other CMIP5 models.

Arid and semi-arid environments correspond to one-third of the Earths terrestrial surface. In these environments, precipitation is an essential and limiting element for vegetation growth and ecosystem biomass productivity. The semi-arid region of Brazil comprises around 11.5% of the national territory, where the Caatinga biome originally composed ~ 76% of this area, with water deficit as a prominent feature, annual rainfall lower than 800 mm, temperatures ranging between 25 and 30 °C, and potential evapotranspiration higher than 2000 mm/year. Research on the dynamics of mass and heat fluxes through techniques such as eddy covariance (EC) has contributed to estimate the magnitude and seasonal patterns of turbulent exchanges between ecosystems and the atmosphere. This study was conducted in an area of dense Caatinga (DC) and another of sparse Caatinga (SC) from 2013 to 2014. It was observed that albedo (α) and net radiation (Rn) were higher in the SC compared with DC since the magnitude of incoming shortwave radiation was higher in this area. It was found that most of the Rn is converted to sensible heat flux (H), mainly during the dry period in the SC, about 50% for H and 20% for λE. The energy balance closure showed that the turbulent fluxes (H + λE) were underestimated in comparison to the available energy at the surface (Rn − G). We also observed that this discrepancy was higher in the DC area, corresponding to ~ 30%.

Deforestation is a threat to biodiversity and the worlds climate. As agriculture and mining areas grow, forest loss becomes unbearable for the environment. Consequently, monitoring deforestation is crucial for decision makers to create polices. The most reliable deforestation data about the Amazon forest is generated by the Brazils National Institute for Space Research (INPE) through its PRODES project. This effort is labor and time intensive because it depends on visual interpretation from experts. Additionally, frequent Amazons atmospheric phenomena, such as clouds, difficult image analysis which induces alternative approaches such as time series analysis. One way to increase the number of images of an area consists of using images from different satellites. NASA provides the Harmonized Landsat and Sentinel-2 (HLS) dataset solving spectral dissimilarities of satellite sensors. In this paper, the possibilities of HLS for forest monitoring are explored by applying two deforestation detection methods, Break Detection for Additive Season and Trend (BFAST) monitor and Random Forest, over four different vegetation indices, NDVI, EVI, GEMI and SAVI. The SAVI index used as input for BFAST monitor performed the best in this data setup with 95.23% for deforested pixel, 53.69% for non-deforested pixels. Although the HLS data is described as analysis ready, further pre-processing can enhance the outcome of the analysis. Especially, since the cloud and cirrus cover in the Amazon causes gaps in the dataset, a best pixel method is recommended to create patched images and thus a continuous time series as input for any land cover and land use classification.

Atmospheric flask samples are either collected at atmospheric pressure by opening a valve of a pre-evacuated flask or pressurized with the help of a pump to a few bar above ambient pressure. Under humid conditions, there is a risk that water vapor in the sample leads to condensation on the walls of the flask, notably at higher than ambient sampling pressures. Liquid water in sample flasks is known to affect the C2 mixing ratios and also alters the isotopic composition of oxygen (O-17 and O-18) in CO2 via isotopic equilibration. Hence, for accurate determination of CO2 mole fractions and its stable isotopic composition, it is vital to dry the air samples to a sufficiently low dew point before they are pressurized in flasks to avoid condensation. Moreover, the drying system itself should not influence the mixing ratio and the isotopic composition of CO2 or that of the other constituents under study. For the Airborne Stable Isotopes of Carbon from the Amazon (ASICA) project focusing on accurate measurements of CO2 and its singly substituted stable isotopologues over the Amazon, an airdrying system capable of removing water vapor from air sampled at a dew point lower than -2 degrees C, flow rates up to 12 L min(-1) and without the need for electrical power was needed. Since to date no commercial air-drying device that meets these requirements has been available, we designed and built our own consumable-free, power-free and portable drying system based on multitube Nafion (TM) gas sample driers (Perma Pure, Lakewood, USA). The required dry purge air is provided by feeding the exhaust flow of the flask sampling system through a dry molecular sieve (type 3A) cartridge. In this study we describe the systematic evaluation of our NafionTm-based air sample dryer with emphasis on its performance concerning the measurements of atmospheric CO2 mole fractions and the three singly substituted isotopologues of CO2 ((OCO)-O-16-C-13-O-16, (OCO)-O-16-C-12-O-17 and (OCO)-O-16-C-12-O-18) as well as the trace gas species CH4, CO, N2O and SF6. Experimental results simulating extreme tropical conditions (saturated air at 33 degrees C) indicated that the response of the air dryer is almost instantaneous and that approximately 85L of air, containing up to 4 % water vapor, can be processed staying below a -2 degrees C dew point temperature (at 275 kPa). We estimated that at least eight flasks can be sampled (at an overpressure of 275 kPa) with a water vapor content below -2 degrees C dew point temperature during a typical flight sampling up to 5 km altitude over the Amazon, whereas the remaining samples would stay well below 5 degrees C dew point temperature (at 275 kPa). The performance of the air dryer on measurements of CO2, CH4, CO, N2O, and SF6 and the CO2 isotopologues (OOO)-O-16-O-13-O-16 and (OCO)-O-16-C-12-O-18 was tested in the laboratory sim- ulating real sampling conditions by compressing humidified air from a calibrated cylinder, after being dried by the air dryer, into sample flasks. We found that the mole fraction and the isotopic composition difference between the different test conditions (including the dryer) and the base condition (dry air, without dryer) remained well within or very close to, in the case of N2O, the World Meteorological Organization recommended compatibility goals for independent measurement programs, proving that the test condition induced no significant bias on the sample measurements.

The large amount of carbon stored in trees and soils of the Amazon rain forest is under pressure from land use as well as climate change. Therefore, various efforts to monitor greenhouse gas exchange between the Amazon forest and the atmosphere are now ongoing, including regular vertical profile (surface to 4.5 km) greenhouse gas measurements across the Amazon. These profile measurements can be used to calculate fluxes to and from the rain forest to the atmosphere at large spatial scales by considering the enhancement or depletion relative to the mole fraction of air entering the Amazon basin from the Atlantic, providing an important diagnostic of the state, changes and sensitivities of the forests. Previous studies have estimated greenhouse gas mole fractions of incoming air (‘background’) as a weighted mean of mole fractions measured at two background sites, Barbados (Northern Hemisphere) and Ascension (Southern hemisphere) in the Tropical Atlantic, where the weights were based on sulphur hexafluoride (SF6) measured locally (in the Amazon vertical profiles) and at the two background sites. However, this method requires the accuracy and precision of SF6 measurements to be significantly better than 0.1 parts per trillion (picomole mole-1), which is near the limit for the best SF6 measurements and assumes that there are no SF6 sources in the Amazon basin. We therefore present here an alternative method. Instead of using SF6, we use the geographical position of each air-mass back-trajectory when it intersects the limit connecting these two sites to estimate contributions from Barbados versus Ascension. We furthermore extend the approach to include an observation site further south, Cape Point, South Africa. We evaluate our method using CO2 vertical profile measurements at a coastal site in Brazil comparing with values obtained using this method where we find a high correlation (r2 = 0.77). Similarly, we obtain good agreement for CO2 background when comparing our results with those based on SF6, for the period 2010-2011 when the SF6 measurements had excellent precision and accuracy. We also found high correspondence between the methods for background values of CO, N2O and CH4. Finally, flux estimates based on our new method agree well with the CO2 flux estimates for 2010 and 2011 estimated using the SF6-based method. Together, our findings suggest that our trajectory-based method is a robust new way to derive background air concentrations for the purpose of greenhouse gas flux estimation using vertical profile data.

The use of matrix by species that naturally inhabit forest fragments can be an important instrument to restore connectivity in fragmented landscapes. The type and structure of the matrix are determinant for this connectivity, however, few studies have explored this theme. In this study, we evaluated the community of small mammals within forest remnants and within two types of matrices (coffee plantation and pasture). In all, 11 species of small mammals were captured, being Akodon montensis, Oligoryzomys nigripes and Calomys cerqueirai the most abundant in fragments, coffee plantation and pasture, respectively. The results show that the composition and structure of the community in the two matrix types are distinct from those found in fragments, and the coffee plantation matrix has greater abundance and greater richness of small mammals than the pasture matrix.

The main objective of this study is to assess the ability of several high-resolution satellite-based precipitation estimates to represent the Precipitation Diurnal Cycle (PDC) over Brazil during the 20142018 period, after the launch of the Global Precipitation Measurement satellite (GPM). The selected algorithms are the Global Satellite Mapping of Precipitation (GSMaP), The Integrated Multi-satellitE Retrievals for GPM (IMERG) and Climate Prediction Center (CPC) MORPHing technique (CMORPH). Hourly rain gauge data from different national and regional networks were used as the reference dataset after going through rigid quality control tests. All datasets were interpolated to a common 0.1◦ × 0.1◦ grid every 3 h for comparison. After a hierarchical cluster analysis, seven regions with different PDC characteristics (amplitude and phase) were selected for this study. The main results of this research could be summarized as follow: (i) Those regions where thermal heating produce deep convective clouds, the PDC is better represented by all algorithms (in term of amplitude and phase) than those regions driven by shallow convection or low-level circulation; (ii) the GSMaP suite (GSMaP-Gauge (G) and GSMaP-Motion Vector Kalman (MVK)), in general terms, outperforms the rest of the algorithms with lower bias and less dispersion. In this case, the gauge-adjusted version improves the satellite-only retrievals of the same algorithm suggesting that daily gauge-analysis is useful to reduce the bias in a sub-daily scale; (iii) IMERG suite (IMERG-Late (L) and IMERG-Final (F)) overestimates rainfall for almost all times and all the regions, while the satellite-only version provide better results than the final version; (iv) CMORPH has the better performance for a transitional regime between a coastal land-sea breeze and a continental amazonian regime. Further research should be performed to understand how shallow clouds processes and convective/stratiform classification is performed in each algorithm to improve the representativity of diurnal cycle.

A pesquisa de percepção ambiental dos moradores da bacia hidrográfica do rio Paraíba do Sul trecho paulista – foi conduzida pelos pesquisadores populares e alunos do curso Cenários da Bacia Hidrográfica do Paraíba do Sul a partir da Educação Ambiental, parte do Projeto Recursos hídricos na bacia do Paraíba do Sul: integrando aspectos naturais e antrópicos, Processo n° 2180/2017, ANA-CAPES, sob coordenação do CCST Centro do Ciência do Sistema Terrestre do INPE. A pesquisa tem por objetivo identificar como os moradores da região percebem questões conceituais relacionadas às temáticas ambientais nas escalas global e local, como se veem enquanto atores nos processos de governança, e se e como a crise hídrica da última década afetou sua rotina. Foram entrevistados 339 moradores da bacia (IC=95%; e 5% de margem de erro), considerando todos os municípios da bacia, a partir dos estratos da população, local de residência, faixa etária e gênero. Esta extensa pesquisa apresentou seis grupos de resultados: i) conceitos gerais sobre meio ambiente; ii) questões ambientais em escala global; iii) questões ambientais em escala local; iv) questão hídrica; v) a crise hídrica; vi) governança. Dentre os principais resultados, foi identificado que os moradores têm dificuldades em compreender o ambiente em sua complexidade e de maneira sistêmica; que a educação ambiental é prioritariamente vista como uma ferramenta vinculada ao ensino formal; que as ameaças globais que se destacaram foram relacionadas às questões urbanas, em especial a poluição urbana. Sobre a questão hídrica, grande parte dos moradores compreendem a relação entre as cidades e os corpos hídricos superficiais, e identificam o rio Paraíba do Sul como principal curso hídrico na região. No entanto, grande parte dos entrevistados desconhecem as estruturas de gestão das águas. Apenas 25% dos entrevistados conhecem os comitês de bacia; e grande parte acredita que o responsável pela gestão das águas são as empresas prestadoras de serviços de saneamento. Tendo em vista os resultados, recomenda-se que as ações de educação ambiental no território da bacia tenham um forte direcionamento político-institucional, no sentido de mobilizar e engajar a população, para que haja um reconhecimento da população como protagonista e agente transformador do seu meio.