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While water lifting plays a recognized role in the global atmospheric power budget, estimates for this role in tropical cyclones vary from no effect to a major reduction in storm intensity. To better assess this impact, here we consider the work output of an infinitely narrow thermodynamic cycle with two streamlines connecting the top of the boundary layer in the vicinity of maximum wind (without assuming gradient-wind balance) to an arbitrary level in the inviscid free tropo-sphere. The reduction of a storm’s maximum wind speed due to water lifting is found to decline with increasing efficiency of the cycle and is about 5% for maximum observed Carnot efficiencies. In the steady-state cycle, there is an extra heat input associated with the warming of precipitating water. The corresponding positive extra work is of an opposite sign and several times smaller than that due to water lifting. We also estimate the gain of kinetic energy in the outflow region. Contrary to previous assessments, this term is found to be large when the outflow radius is small (comparable to the radius of maximum wind). Using our framework, we show that Emanuel’s maximum potential intensity (E-PI) corresponds to a cycle where total work equals work performed at the top of the boundary layer (net work in the free troposphere is zero). This con-strains a dependence between the outflow temperature and heat input at the point of maximum wind, but does not constrain the radial pressure gradient. We outline the implications of the established patterns for assessing real storms.

The Atlantic forest is one of the world’s major tropical biomes due to its rich biodiversity. Its vast diversity of plant species poses challenges in floristic surveys. Fourier transform infrared spectroscopy (FTIR) enables rapid and residue-free data collection, providing diverse applications in organic sample analysis. FTIR spectra quality depends on the sample preparation methodology. However, no research on FTIR spectroscopy methodology for taxonomy has been conducted with tropical tree species. Hence, this study addresses the sample preparation influence on FTIR spectra for the taxonomic classification of 12 tree species collected in the Serra do Mar State Park (PESM) – Cunha Nucleus São Paulo State, Brazil. Spectra were obtained from intact fresh (FL), intact dried (DL), and heat-dried ground (GL) leaves. The spectra were evaluated through chemometrics using Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Linear Discriminant Analysis (LDA) with validation by LDA-PCA. The results demonstrate that sample preparation directly influences tropical species FTIR spectra categorization capability. The best taxonomic classification result for all techniques, validated by LDA-PCA, was obtained from GL. FTIR spectra evaluation through PCA, HCA, and LDA allow for the observation of phylogenetic relationships among the species. FTIR spectroscopy proves to be a viable technique for taxonomic evaluation of tree species in floristic exploration of tropical biomes which can complement traditional tools used for taxonomic studies.

Wildfires have been causing negative effects on ecosystems and rural communities. Among rural communities, the agrarian reform settlement projects have registered fires resulting from agricultural management inside and outside their areas. In this context, our objective was to analyze 821 settlement projects in the Matopiba region to explore the spatial-temporal dynamics of burned area occurrences. For this, we used the burned area data from MCD64A1 v006, from 2001 to 2021, and estimated the total burned area and its percentage for each settlement project per month and per year, and the frequency and trend. Based on these characteristics, we classified each settlement project to identify patterns. We identified a temporal pattern, with inter-annual variations, associated with the dry season. Also, the extension of the burned area increased significantly in the years of drought anomaly. Settlement projects with high and low fire frequency coexist in the same region. We also identified a small cluster with a positive trend in the northeast of the Matopiba region related to the surrounding agriculture expansion area. The classification based on burned area, trend and frequency is useful to select priority settlement projects for fire prevention actions.

Understanding the trends and uncertainties in Building Energy Simulation (BES) performance indicators under future climate conditions is crucial for mitigating issues such as overheating and power outages. To address this, we generated a set of weather files for all 27 state capitals in Brazil, considering six climate model projections (three General Circulation Models as driving models and two nested Regional Climate Models) and two distinct emission scenarios from the CORDEX project. We analyzed the variability in climatic variables and subsequently performed BES on a representative Brazilian social housing unit to evaluate its impact on the performance indicators outcomes. Consistent with previous studies, a substantial increase in cooling-related demands was observed in the more pessimistic scenario (RCP8.5) and mild increases in the more optimistic scenario (RCP2.6), with a trend toward stabilization after 2050. Regarding uncertainties, we found higher Relative Standard Deviation (RSD) values for the cooling degree hours indicator. The capitals in the Central-West, Southeast, and South regions exhibited greater uncertainty regarding temperature indicators, whereas the irradiation parameters displayed higher uncertainties in the Northeast region. For the BES outcomes, RSD values as high as 19.9% were found for cooling load values. It was also demonstrated that locations, periods, and scenarios exhibit different extreme climate model projections. Ideally, employing an ensemble of weather files developed from other models would help assess associated uncertainties in the building performance indicators.

The increase in greenhouse gasses (GHG) anthropogenic emissions and deforestation over the last decades have led to many chemical and physical changes in the climate system, affecting the atmosphere’s energy and water balance. A process that could be affected is the Amazonian moisture transport in the South American continent (including La Plata basin), which is crucial to the southeast Brazilian water regime. The focus of our research is on evaluating how local (i.e. Amazon deforestation) and global forcings (increase of atmospheric GHG concentration) may modify this moisture transport under climate change scenarios. We used two coupled land-atmosphere models forced by CMIP6 sea surface temperatures to simulate these processes for two scenarios: i) increase in carbon dioxide (CO2) RCP8.5 atmospheric levels (00DEF), and ii) total Amazon deforestation simultaneous with atmospheric CO2 levels increased (100DEF). These scenarios were compared with a control simulation, set with a constant CO2 of 388 ppm and present-day Amazon Forest cover. The 30-year Specific Warming Level 2 (SWL2) index evaluated from the simulations is set to be reached 2 years earlier due to Amazon deforestation. A reduction in precipitation was observed in the Amazon basin (−3.1 mm·day−1) as well as in La Plata Basin (−0.5 mm·day−1) due to reductions in the Amazon evapotranspiration (−0.9 mm·day−1) through a stomatal conductance decrease (00DEF) and land cover change (100DEF). In addition, the income moisture transport decreased (22 %) in the northern La Plata basin in both scenarios and model experiments. Our results indicated a worse scenario than previously found in the region. Both Amazon and La Plata hydrological regimes are connected (moisture and energy transport), indicating that a large-scale Amazon deforestation will have additional climate, economic and social implications for South America.

Projections of future carbon sinks and stocks are important because they show how the world’s ecosystems will respond to elevated CO2 and changes in climate. Moreover, they are crucial to inform policy decisions around emissions reductions to stay within the global warming levels identified by the Paris Agreement. However, Earth System Models from the 6th Coupled Model Intercomparison Project (CMIP6) show substantial spread in future projectionsespecially of the terrestrial carbon cycle, leading to a large uncertainty in our knowledge of any remaining carbon budget (RCB). Here we evaluate the global terrestrial carbon cycle projections on a region-by-region basis and compare the global models with regional assessments made by the REgional Carbon Cycle Assessment and Processes, Phase 2 activity. Results show that for each region, the CMIP6 multi-model mean is generally consistent with the regional assessment, but substantial cross-model spread exists. Nonetheless, all models perform well in some regions and no region is without some well performing models. This gives confidence that the CMIP6 models can be used to look at future changes in carbon stocks on a regional basis with appropriate model assessment and benchmarking. We find that most regions of the world remain cumulative net sources of CO2 between now and 2100 when considering the balance of fossil-fuels and natural sinks, even under aggressive mitigation scenarios. This paper identifies strengths and weaknesses for each model in terms of its performance over a particular region including how process representation might impact those results and sets the agenda for applying stricter constraints at regional scales to reduce the uncertainty in global projections.

Anthropogenic disturbances directly influence environmental processes and increase the concentration of carbon (C) in the atmosphere. Here, we compare the differences in the seasonality of the balance of carbon, energy, and radiation, as well as seek to identify the interrelationships between these environmental variables and their impact on the growth of Opuntia cactus. Data were acquired from an eddy covariance flux tower over a cactus crop agroecosystem (2019-2021) in the Brazilian semi-arid region. In addition, we use plant growth rates, carbon and nutrient stocks, evapotranspiration (ET) and water use efficiency (WUE), and radiation (RUE). We show that the closure of the surface energy balance was 71%, although there are minimal fluxes of available energy lost (29%) by unquantified processes. At all seasons, the highest net ecosystem CO2 exchange (NEE) rate was between 11:00-13:00 (-5.75 mu mol m- 2 s- 1). During the dry and wet-dry season, there was the lowest daily gross primary productivity (GPP) (2.5 mu mol m- 2 s- 1) and net radiation-Rn (217.97 W m-2). Ecosystem respi-ration was more expressive during the wet season (2.41 mu mol m- 2 s- 1), and maximum diurnal value of 2.65 mu mol m- 2 s- 1. Furthermore, the latent heat flux was higher during the wet season (114.68 W m-2) and lowered in the dry season (9.39 W m-2). The net assimilation rate showed higher values during the dry-wet transition. The dry season presented higher nutrient use efficiency and WUE (14.77 g m- 2 mm -1). The highest ET occurred during the wet season (227 mm), and RUE was 81.48% higher than in the dry season. Overall, the cactus was a potential C sink during the three years of assessment (NEE:-377 g C m- 2 year- 1; GPP: 881 g C m- 2 year- 1). The results help us to understand that most of the Rn energy is used in the sensible heat flux (58% ratio).

Investigamos o efeito de eventos de sobreirradiância em inversores para diferentes tecnologias de módulos (CdTe, CdTe ARC, mc-Si), buscando indícios de perda de potência DC/AC e correntes DC capazes de causar efeitos deletérios nos fusíveis dos sistemas em estudo. Analisamos uma série de dados de três anos de medições de irradiância solar e produção fotovoltaica, registrados em um sistema experimental localizado no laboratório FOTOVOLTAICA UFSC, Florianópolis, Brasil. Identificamos e caracterizamos eventos de sobreirradiância solar (OIEs) e eventos de sobreirradiância solar extremos (EOIEs). Foram analisadas as variáveis de entrada e de saída em inversores fotovoltaicos durante tais eventos. Foi evidenciada variabilidade na composição espectral de EOIEs. Na localidade estudada, não foram detectados eventos com duração maior de 1 minuto capazes de causar clipping de inversor ou efeitos deletérios, porém em diversas ocasiões foram observados eventos limítrofes.

Here we analyze the trends of rainfall and the frequency of rainy days over the Brazilian Cerrado between 1960 and 2021 in four distinct periods according to the seasonal patterns over the region. We also evaluated trends in evapotranspiration, atmospheric pressure, winds, and atmospheric humidity over the Cerrado to elucidate the possible reasons for the detected trends. We recorded a significant reduction in rainfall and frequency of rainy days in the northern and central Cerrado regions for all periods except at the beginning of the dry season. The most pronounced negative trends were recorded during the dry season and the beginning of the wet season, where we recorded reductions of up to 50% in total rainfall and the number of rainy days. These findings are associated with the intensification of the South Atlantic Subtropical Anticyclone, which has been shifting atmospheric circulation and raising regional subsidence. Moreover, during the dry season and the beginning of the wet season, there was a reduction in regional evapotranspiration, which also potentially contributed to the rainfall reduction. Our results suggest an expansion and intensification of the dry season in the region, potentially bringing broad environmental and social impacts that transcend the Cerrado boundaries.

Fire has been an intrinsic ecological component of the ecosystems, affecting the public, economic, and socio-cultural policies of human-nature interactions. Using fire over grassland vegetation is a traditional practice for livestock in the highland grasslands and has economic and environmental consequences that have not yet been understood. A better description of the spatio-temporal biomass burning patterns is needed to analyze the effects of creation and application in these areas. This study used remote sensing techniques based on Sentinel-2 data and machine learning algorithms to identify burning scars and compare them with a national fire collection database for the highland grasslands in the Atlantic Forest Biome in Brazil. The aim is to evaluate public management tools and legislation evolution during the 35 years of the time series analyzed. The results indicated that 12,285 ha of grasslands were converted to other uses, losing about 24% of their original formation, with 10% occurring after banned this practice in 2008. The burned areas classification using the Random Forest algorithm obtained an AUC = 0.9983. Divergences in the burned area’s extent and frequency were found between the municipality’s authorized license and those classified as burned. On average, only 43% of the burned area in the Parque Estadual do Tainhas and its buffer zone had an environmental permit in the last 5 years. This research’s results provide subsidies for revising and creating public policies and consequently help territorial management.

We present the frst convection-permitting regional climate model (CPRCM) simulations at 4.5 km horizontal resolution for South America at near-continental scale, including full details of the experimental setup and results from the reanalysisdriven hindcast and climate model-driven present-day simulations. We use a range of satellite and ground-based observations to evaluate the CPRCM simulations covering the period 19982007 comparing the CPRCM output with lower resolution regional and global climate model confgurations for key regions of Brazil. We fnd that using the convection-permitting model at high resolution leads to large improvements in the representation of precipitation, specifcally in simulating its diurnal cycle, frequency, and sub-daily intensity distribution (i.e. the proportion of heavy and light precipitation). We tentatively conclude that there are also improvements in the spatial structure of precipitation. We see higher precipitation intensity and extremes over Amazonia in the CPRCMs compared with observations, though more sub-daily observational data from meteorological stations are required to conclusively determine whether the CPRCMs add value in this regard. For annual mean precipitation and mean, maximum and minimum near surface temperatures, it is not clear that the CPRCMs add value compared with coarser-resolution models with parameterised convection. We also fnd large changes in the contribution to evapotranspiration from canopy evaporation compared to soil evaporation and transpiration compared with the RCM. This is likely to be related to the shift in precipitation intensity distribution of the CPRCMs compared to the RCM and its impact on the hydrological requires further investigation.

Correction to: Nature Food, published online 31 January 2022. This paper was originally published under a standard Springer Nature license (© The Author(s), under exclusive licence to Springer Nature Limited). It is now available as an open-access paper under a Creative Commons Attribution 4.0 International license, © The Author(s). The error has been corrected in the online version of the article.