According to data obtained from meteorological towers, Brazil has significantly increased temperature in the past 20 years, particularly in the North and Midwest regions. Vapor pressure deficit and evapotranspiration were also analyzed, showing an increase across the entire country, confirming that the air is becoming drier. This warming trend is part of the global climate change phenomenon caused by the rise of greenhouse gases in the atmosphere, fires, poor soil management practices, deforestation, and logging. The increase in temperature and dryness has profoundly impacted Brazil’s climate and ecosystems, leading to intensified extreme weather events and changes in the distribution of both animal and plant species. This study highlights the importance of utilizing meteorological tower data to monitor and understand the effects of climate change in Brazil. It emphasizes the need for immediate action to address its causes and mitigate its negative impacts.

A temperatura e a umidade relativa do ar são de grande importância para o entendimento da dinâmica dos fluxos de CO2, taxas de evapotranspiração e estudos de microclima. Nesse sentido, o presente trabalho analisou a variação mensal da evapotranspiração de referência (ET0), temperatura e umidade relativa do ar na região do Pantanal Mato-grossense. Os dados foram obtidos de uma torre micrometeorológica instalada na Base Avançada de Pesquisas do Pantanal (BAPP) da Universidade Federal de Mato Grosso (UFMT), localizada no Parque SESC Baía das Pedras em Porto Cercado, Poconé – MT. A partir dos dados analisados no período de 2017 a 2019, percebeu-se a ocorrência de oscilações mensais e anuais na evapotranspiração. Em relação às análises dos dados de temperatura e umidade relativa do ar, concluiu-se que no período de seca, que acontece no inverno do Pantanal, os dados de temperatura e umidade do ar são baixas. Enquanto no período chuvoso e de cheia, que acontecem durante o verão, as temperaturas e umidade relativa do ar são altas.

In this study, data collected from 2000 to 2019 on vapor pressure deficit ($VPD$) and its relationship with micrometeorological variables (fire occurrences, aerosol concentration, temperature, and carbon flux) were analyzed in six locations situated in different Brazilian ecosystems: Rio Branco, AC; Manaus, AM; Alta Floresta, MT (within the Amazon Rainforest); Baia das Pedras, MT (Pantanal); Fazenda Miranda, MT (Cerrado); and Petrolina, PE (northeastern semiarid region). Temporal series analysis of $VPD$ was conducted by determining the principal component of singular spectrum analysis (SSA) for this variable in all locations. It was observed that the main component of SSA for $VPD$ is sensitive to local land-use changes, while no evidence of large-scale influences related to global climate change was observed. A strong coupling between $VPD$ values and local maximum temperature with monthly fire occurrence and logarithmic aerosol concentration profiles was also observed. The results of the study are discussed in the context of the ecosystems’ carbon sequestration capacity. The combined results of the study indicate a scenario in which local land-use changes can compromise the capacity of Brazilian ecosystems to absorb carbon.

Atmospheric aerosols significantly influence climate systems and hydrological processes, but their impacts on evapotranspiration remain insufficiently understood, particularly in tropical savanna regions. This study investigates the direct and indirect effects of aerosol optical depth (AOD) on reference evapotranspiration ($E{T}_0$) in the Mato Grosso Cerrado, Brazil, a biome characterized by pronounced seasonal climatic variations. Using data collected from the AERONET network at Fazenda Miranda, AOD was analyzed alongside meteorological variables such as air temperature, global radiation, and $E{T}_0$, estimated using the FAO Penman–Monteith method. The results reveal distinct seasonal patterns, with aerosols having a more pronounced influence during the dry season. Positive correlations were observed between AOD and air temperature, while negative correlations were found between AOD and global radiation, especially during the dry season. The relationship between AOD and $E{T}_0$ varied between years and seasons, with significant reductions in $E{T}_0$ linked to high aerosol concentrations during the dry period. These findings demonstrate that aerosols play a critical role in modulating evapotranspiration and radiation balance, particularly in regions affected by biomass burning. This study provides valuable insights into the interplay between aerosols, climate variables, and hydrological processes, contributing to a better understanding of aerosols’ impacts on tropical ecosystems.

O Pantanal brasileiro é um bioma sazonalmente inundável, onde a compreensão microclimática é indispensável para compreender a importância desse bioma em escala global. O objetivo principal deste estudo foi analisar a dinâmica dos fluxos de radiação de onda longa no Pantanal, bem como as implicações de suas variações sazonais e interanuais na micrometeorologia da região. O estudo foi realizado em uma área sazonalmente inundável no Pantanal brasileiro no estado de Mato Grosso entre 16°29’04"e 16°29’10” S; e entre 56°25’25 "e 56°25’36" no sítio experimental localizado na Reserva do Patrimônio Natural (RPPN), assistido pelo Serviço Social do Comércio, conhecido como SESC-Pantanal, local no qual a estação meteorológica automática mensura e armazena a radiação solar, temperatura do ar e do solo, velocidade do vento e precipitação onde foi calculado a evapotranspiração, índice de aridez, fluxo de calor sensível e latente. Há uma maior amplitude da temperatura do ar no período seco (maio a setembro) em função de frentes frias, já no período chuvoso a média de temperatura, Rn e ETo é maior devido a influência da água superficial e maior radiação incidente. A sazonalidade das águas no Pantanal influencia diretamente na temperatura, balanço de energia, evapotranspiração e umidade relativa. Palavras-chave: micrometeorologia; fluxo de energia; área inundável; Razão de Bowen. Dynamics of long-wave radiation flows in the Pantanal Mato-Grossense The Brazilian Pantanal is a seasonally flooded biome, where microclimatic understanding is essential to understand the importance of this biome on a global scale. The main objective of this study was to analyze the dynamics of longwave radiation fluxes in the Pantanal, as well as the implications of their seasonal and interannual variations on the region's micrometeorology. The study was carried out in a seasonally floodable area in the Brazilian Pantanal in the state of Mato Grosso between 16°29'04" and 16°29'10" S; and between 56°25'25" and 56°25'36" at the site experimental located in the Natural Heritage Reserve (RPPN), assisted by the Social Service of Commerce, known as SESC-Pantanal, where the automatic meteorological station measures and stores solar radiation, air and soil temperature, wind speed and precipitation where evapotranspiration, aridity index, sensible and latent heat flux were calculated. There is a greater range of air temperature in the dry period (May to September) due to cold fronts, while in the rainy period the average temperature, Rn and ETo is greater due to the influence of surface water and greater incident radiation. The seasonality of water in the Pantanal directly influences temperature, energy balance, evapotranspiration and relative humidity. Keywords: micrometeorology; energy flow; floodable area; Bowen Ratio.