Publicações

The Digital Terrain Model (DTM) is an important product used in geosciences, but its extraction in dense forest areas is still a challenge. One of the major difficulties in extracting a DTM via remote sensors is in dense forest areas, as the generated information becomes degraded due to the fact that the most commonly used techniques can only measure canopy elevation and not terrain elevation, limiting cartography in areas such as the Amazon. The most appropriate technique for extracting a DTM is airborne LiDAR (Light Detection And Ranging), but there are limitations of time and cost for large areas. P-band radar waves have a great capacity for penetrating through dense vegetation, making it a promising tool for digital terrain modeling in forested areas. This technique was used for the latest update of the cartography of the Amapá state (Brazil). This article aims to evaluate the overall quality of a DTM produced using airborne P-band radar interferometry in relation to LiDAR data (used as a reference) in 4 regions of the Amapá state, using various criteria. In addition to the visual comparison confirming the general similarity of the two products, the difference in terms of elevation and slope was evaluated, with an average error in elevation of-0.52 m, while having a standard deviation and average RMSE below 3 meters, with a difference in slope of approximately-4° and a standard deviation and average RMSE of 4.74° and 6.14°, respectively. This study provides an estimate of the accuracy of P-band radar DTM, both in terms of elevation and slope, which are essential variables for characterizing landforms.

The vertical structure of forests provides important parameters for estimating aboveground biomass (AGB) and it can be measured by lidar sensors. The Global Ecosystem Dynamics Investigation (GEDI) full-waveform lidar sensor collects data systematically over the Earths surface from the International Space Station. Since GEDI became operational, it has collected billions of ~25-m diameter footprints. This massive dataset has been used to create higher level gridded and non-grided products. However, GEDIs ~25-m footprints can be subject to errors associated with effects of geolocation, terrain slope, and beam sensitivity, among others, which are likely transferred to the downstream products. This study aims to (1) evaluate the effect of beam sensitivity and terrain slope on the accuracy of relative heights (RH) of GEDI product L2A version 2 through comparison with discretereturn airborne lidar data collected over transects in the Brazilian Amazon Forest biome, (2) assess GEDIs geolocation uncertainty and investigate its combined effects with beam sensitivity and terrain slope, and (3) reevaluate beam sensitivity and terrain slope effects on the GEDI L2A RHs using footprints that were geolocationadjusted through a simple novel approach. The analysis separates GEDI footprints by acquisition time, i.e., daytime, nighttime, and combined (all-data). The discrete-return airborne lidar point clouds are used to derive terrain slope within the GEDI footprints and to simulate GEDI waveforms and derive RHs comparable to the GEDI L2A product. Results indicate that terrain slope only causes significant effects on GEDI data collected during daytime because solar radiation affects waveform signal-to-noise ratio. Beam sensitivity causes significant effects on nighttime and all-data GEDI L2A RHs. If geolocation uncertainty is considered, the effects of beam sensitivity and terrain slope have just minor changes. Geolocation-adjusted data continue showing significant effects on nighttime and all-data RH differences caused by beam sensitivity but produce unbiased results. This study improves the understanding of how beam sensitivity, terrain slope, and their combined effect with geolocation uncertainty may affect the GEDI L2A RH collected over the Brazilian Amazon forest during daytime and nighttime.

The joint effects of climate change and landscape fragmentation to the genetic viability of isolated populations has barely been addressed for the Atlantic Forest fauna. Therefore, this work explored the potential habitat suitability for the southern muriqui (Brachyteles arachnoides), by modeling climate change, landscape fragmentation, and genetic diversity loss of the species. Maxent was used to model its potential distribution in 2050, with two climate change scenarios. A land use and land cover change model was applied to describe current and future forest fragmentation patterns, and a Population and Habitat Viability Analysis (PHVA) was used to describe the retention of genetic diversity of the southern muriqui. Although PHVA modeling provided a low risk of extinction of the southern muriqui, climate change and fragmentation could result in the loss of >65% of the suitable forest patches, and reduce the habitat suitability to only 11% of the potential distribution area, which could lead to future genetic diversity loss and decreased capacity of self-sustained populations. In both climate change scenarios, the suitable areas for the southern muriqui in Paraná and Rio de Janeiro states will decrease more drastically. Areas where the primate occurs in the interior of São Paulo and Rio de Janeiro states will disappear or be climatically disconnected from the core potential habitat. Alike preventing further deforestation, Atlantic Forest restoration actions are needed to connect the viable populations for compensating the projected land use and climate change impacts to the long term persistence of the southern muriqui.

In Brazil, conservation priority zones, in spite of their key role in preserving natural vegetation and its environmental resources are frequently located outside the country’s public network of protected areas (PAs). Here we present the first study on land-use impacts inside Brazil’s unprotected (i.e. outside PAs) Cost-Effective conservation priority Zones (CEZs), for the period 2020-2050. CEZs are conservation priority zones that had experienced low levels of human impact in 2020. In this study, we consider various governance scenarios, including different deforestation control and native vegetation restoration policies. To this end, a land-use change model is combined with a downscaling method to generate natural vegetation cover projections at a 0.01? resolution. Results, which include the effects of climate change on the expansion of the Brazilian agriculture, project native vegetation losses (through deforestation) or gains (through restoration) inside unprotected CEZs. If the current pattern of disregard for the environment persists, our results indicate that a large share of the native vegetation inside Brazil’s CEZs is likely to disappear, with negative impacts on biodiversity preservation, green-house gas emissions and ecosystem services in general. Moreover, even if fully implemented and enforced, Brazil’s current Forest Code is insufficient to adequately protect CEZs from anthropization, especially in the Cerrado biome. We expect that this study can help improving the conservation and restoration of CEZs in Brazil.

The Amazon is one of the most important tropical forests in the world because it is a key in the regulation of the global climate. It is the world’s largest rainforest, where interactions between the forest and the atmosphere are fundamental to rainfall throughout South America and have an indirect effect on all the regions around the world. Furthermore, the Amazon region may be a source of aerosol that will act as cloud condensation nuclei (CCN). During the rainy season over the Amazon region, in which intense convective activity associated with the South America Monsoon System (SAMS) prevents fires, the primary sources of aerosols include biogenic emissions, dust from the Sahara Desert, and emissions from burning biomass transported from Africa. Besides that, the downward transport of aerosols from the upper troposphere (UT) has been considered a source of particles to the lower troposphere. The particles in the UT over the tropics region have been one of the largest aerosol reservoirs in the atmosphere, which could be from primary aerosols, such as dust, organic carbon and black carbon or secondary aerosol formed by trace gases in the free troposphere. The existence of an aerosol layer at the tropopause level has been observed during June, July, and August in Asia and North America (Asian Tropopause Aerosol Layer – ATAL and North American Tropopause Aerosol Layer – NATAL, respectively) associated with the deep convection of the Monsoons System. Therefore, the aerosol enhancement in the UT and lower stratosphere (LS) and the formation of an aerosol layer over the Amazon region associated with the deep convection of the SAMS during the austral summer are investigated. In the past, field campaigns over South America (SA) (GoAmazon2014/5 experiment) showed aerosol enhancement in the UT. They suggested that new aerosol particles are formed in the UT from biogenic volatile organic material that goes up by upward transport associated with the deep convection. The enhancement of aerosol backscatter values over SA is observed from October to January; it gradually decreases during the following months. The aerosol backscatter inferred from MERRA-2 Reanalysis showed a maximum value of the 2.24×10-5 km-2sr-1 over the Amazon during November and December. The results showed the first evidence of the existence of the South American Tropopause Aerosol Layer (SATAL) that covers the tropical SA and vertically extends up to 80hPa (approximately 18 km), similar to ATAL, and NATAL. The aerosol backscatter inferred from MERRA-2 reanalysis was validated using the attenuated backscatter by CALIOP from CALIPSO satellite. However, field campaigns such as the CAFE-BRAZIL campaign (Chemistry of the Atmosphere: Field Experiment in Brazil), which will be during December/2022 and January/2023 using the HALO (High Altitude Long Range Aircraft) aircraft, are necessary to study the formation of SATAL.

 In this paper we analyze electric-field and current measurements of upward leaders induced by a downward negative lightning flash that struck a residential building. The attachment process was recorded by two high-speed cameras running at 37,800 and 70,000 images per second and the current measured in two lightning rods. Differently from previous works, here we show, for the first time, current measurements of multiple upward leaders that after initiation propagate to connect the negative downward moving leader. At the beginning of the propagation of the leaders that initiate on the instrumented lightning rods, current pulses appear superimposed to a steadily increasing DC current. The upward leader current pulses increase with the approach of the downward leader and are not synchronized but present an alternating pattern. All 2D leader speeds are approximately constant. The upward leaders are slower than the downward leader speed. The average time interval between current pulses in upward leaders is close to the interstep time interval found by optical or electric field sensors for negative cloud-to-ground stepped leaders. The upward leaders respond to different downward propagating branches and, as the branches alternate in propagation and intensity, so do the leaders accordingly. Right before the attachment process the alternating pattern of the leaders ceases, all downward leader branches intensify, and consequently upward leaders synchronize and pulse together. The average linear densities for upward leaders (49 and 82 mu C/m) were obtained for the first time for natural lightning. Plain Language Summary The effectiveness of a lightning protection system depends on its efficiency to intercept the down coming leader of a cloud-to-ground lightning flash. The interception is usually done by an upward connecting leader that initiates from grounded structures, humans, or living beings that protrude from nearby ground. The understanding of the upward connecting leader and of the attachment process with the downward leader plays an important role in the determination of the zone of protection and therefore in the improvement of a lightning protection system. Unconnected upward leaders, that is, upward leaders that fail to connect the downward leader, are also of great importance in lightning protection. They can be large enough to cause damage to equipment vulnerable to sparks or induced currents, and enough to injure people from who it initiates. In this paper we analyze electric-field, speed, and current measurements of upward leaders induced by a downward negative lightning flash that struck a residential building. The attachment process was simultaneously recorded by two high-speed cameras, an electric-field sensor, and current sensors installed on two lightning rods. Differently from previous works we show, for the first time, current measurements of multiple upward leaders induced by the negative downward moving leader.

Este trabalho tem por objetivo identificar as desigualdades do acesso domiciliar à rede de abastecimento de água e de esgotamento sanitário na Região Metropolitana do Rio de Janeiro, RJ, Brasil. Com dados do Censo Demográfico (2010) e de Uso e Cobertura do Solo, um método dasimétrico desagregou os dados censitários, considerando um espaço celular. A dependência espacial do acesso foi estudada por análise espacial exploratória dos Índices de Moran Global e Local. Os resultados indicaram dependência espacial de acesso ao abastecimento de água e esgotamento sanitário e clusters (Alto-Alto) para os dois tipos de serviços sobretudo na capital, Rio de Janeiro, e municípios limítrofes a oeste, além dos municípios Niterói e São Gonçalo, a leste. Esta análise das desigualdades espaciais contribui para o planejamento e adequação de políticas de saneamento.

Species distribution models (SDMs) are one of the most widely used tools to predict areas with potential for occurrence of native, invasive and endangered species, based on current and future environmenal and climate conditions. Despite their global use, evaluating the accuracy of SDMs based only on presence records is still a challenge. The performance of models depends on the sample size and species prevalence. Recently, studies to model the distribution of species in the Caatinga biome in Northeast Brazil have gained force, raising the question about the minimum number of presence records adjusted to different prevalences that are necessary to generate accurate SDMs. In this context, the objective of this study was to indicate minimum numbers of presence records for species with different prevalences in the Caatinga biome to obtain accurate SDMs. For that purpose, we used a method involving simulated species and performed repeated evaluations of the models performance in function of the sample size and prevalence. The results indicated that for this approach in the Caatinga biome, the minimum required numbers of specimen records were 17 and 30 for species with narrow and widespread distributions, respectively.

Desde o século XVIII o Rio de Janeiro é afetado por eventos extremos de precipitação, os quais acarretam uma série de transtornos no espaço urbano, por meio de inundações e movimentos de massa. Dentre inúmeros eventos, o ocorrido no dia quatorze de fevereiro de 2018, possui características peculiares, uma vez que precipitou 51 mm em 1h. Dessa forma, objetivou-se, através da análise rítmica, compreender o evento de maneira dinâmica, dando atenção aos impactos causados na bacia do rio Piraquê-Cabuçu, no município do Rio de Janeiro. Para tal, foram levantados dados para a caracterização da gênese do fenômeno, buscando individualizar os tipos de tempo atmosféricos, através do acompanhamento de seus ritmos. Para a consecução do objetivo, no que tange ao arcabouço metodológico, o estudo recorreu a dados meteorológicos e maregráficos, imagens de satélite, radar meteorológico, cartas sinóticas, dados de reanálise e o Diagrama de Skew-T Log P, além de dados hemerográficos. Com tudo, muito provavelmente o episódio de inundação esteve associado à ocorrência de um evento de downburst, pois os dados corroboram a existência de uma amálgama de condicionantes meteorológicos característicos de tais processos: perda de sustentação e consequente movimento descente de uma parcela de cumulonimbus, o total pluviométrico concentrado e os elevados índices de instabilidade, como o valor de 1.198 J/kg para o índice CAPE. Dadas características genéticas do evento, além do alto grau de antropização da bacia, como consequência os impactos afetaram cerca de 50.000 pessoas e provocaram repercussões na área de estudo por, pelo menos, 7 dias.

O Brasil muitas vezes é caracterizado pela abundância de água, entretanto eventos recorrentes de escassez hídrica nas diversas regiões do País e os múltiplos impactos que podem ser desencadeados e intensificados pelo processo de mudanças climáticas, demonstram a importância da gestão contínua desse recurso. Uma região que tem sido considerada uma alternativa para garantir as demandas hídricas de importantes centros para o desenvolvimento do País, tanto internos como externos as suas fronteiras, é a Bacia do Paraíba do Sul (BPS). Considerando a importância da transposição da BPS para a bacia do Guandú para o atendimento das demandas hídricas e energéticas da região metropolitana do Rio de Janeiro, o presente trabalho tem como objetivo a análise da variabilidade futura dos recursos hídricos, tendo como principal foco a transposição para a bacia do Guandú, e a variabilidade da geração de energia BPS, considerando o processo de mudanças climáticas. A comparação das projeções das vazões e quantidade de energia gerada em cenários futuros com o cenário de referência, mostram uma elevada influência dos processos climáticos nas variações da disponibilidade hídrica da bacia, além de uma tendência geral de redução da disponibilidade hídrica, principalmente nos cenários de maiores emissões de gases do efeito estufa.

Cities are increasingly vulnerable to climate change’s impacts and poorly adapted to extreme variability. This study aimed to evaluate climate projections of air temperature and precipitation in seven cities in the Metropolitan Region of São Paulo that correspond to the Greater ABC Paulista. We used high-resolution models Eta-HADGEM2_ES (CMIP5), CNRM-CM6-1-HR (CMIP6), and the TerraClimate database to analyze future projections and the specific warming levels (SWLs), respectively. Model data were validated with observed data and bias was removed. A bias correction factor was generated and used in the climate projections for the different emission scenarios. The results show a consensus between the models and the SWLs (2 and 4°C) for the increase in maximum (Tmax) and minimum (Tmin) temperatures for all municipalities in ABC Paulista in different emission scenarios until the end of the 21st century. For the nearest future (20202040), the city of São Caetano do Sul (SCS) shows the highest positive annual anomalies of Tmax concerning the climatological period (19852015), for the scenario RCP4.5 (2.8°C) and the RCP8.5 (7.4°C), according to projections from the Eta-HADGEM2_ES, highlighting summer and autumn as the hottest. For precipitation, there was a consensus between the Eta-HADGEM2_ES and the CNRM-CM6-1-HR for a reduction in all scenarios and time-slices 20202040 and 20412070. The municipalities of Diadema (−78.4%) and SCS (−78%) showed the most significant reductions in December for the RCP8.5, and for SSP5-8.5, SCS shows −30.9% in December for the 20202040 time-slice. On the other hand, TerraClimate presents excess rain for Ribeirão Pires (+24.8%) and Santo André (+23.7%) in winter for SWL4°C. These results suggest that an increase in Tmax and Tmin, as projected, should influence the intensity of extreme heat events. Furthermore, a reduction in annual and seasonal rainfall does not mean a decrease in the region’s extreme daily events that cause floods and landslides. However, it leaves an alert of water scarcity for the supply and demand of the population. ABC Paulista does not have adaptation plans to face extreme climate change. The results can contribute to the first phase of creating an adaptation plan, giving a first view of the climate threat that should intensify until the end of the twentieth century affecting the most vulnerable municipalities.

The western tropical North Atlantic (WTNA) is a very complex region, with the influence of intense western boundary currents in connection with equatorial zonal currents, important atmospheric forcings (e.g Intertropical Convergence Zone), mesoscale activities (e.g NBC rings), and the worlds largest river discharge as the Amazon River runoff. The volume discharge is equivalent to more than one-third of the Atlantic river freshwater input, with a plume that spreads over the region reaching the northwestward Caribbean Sea and eastward longitudes of 30°W, and influencing from physical to biological structures. Therefore, in order to enable and encourage more understanding of the region, here we present a dataset based on an idealized scenario of no river runoff of the Amazon River and Par ́a River in the WTNA. The numerical simulations were conducted with a regional oceanic modeling system (ROMS) model and three pairs of files were generated with the model outputs: (i) ROMS-files, with the parameters of the ROMS-outputs raw data in a NetCDF format and monthly and weekly frequencies; (ii) MATLAB-files, which contain oceanographic parameters also in monthly and weekly frequencies; and (iii) NetCDF-files, with oceanographic parameters again in monthly and weekly frequencies. For each file, we present the coordinates and variable names, descriptions, and correspondent units.