Analysis of Fire Radiative Power in Amazon Forest by Satellite: Evaluation with MODIS and VIIRS Sensors

This study aims to investigate the dynamics of forest fires in Brazil, particularly in the Amazon region, motivated by the fact that approximately 60% of the Amazon rainforest lies within Brazilian territory, thus making the country central to the understan-ding and managing this critical environmental issue. Forest fires in the Brazilian forests, especially within the Amazon, represent a major environmental challenge, with significant impacts on biodiversity, atmospheric composition, and climate regulation. In recent decades, fire activity has intensified due to climate variability and growing anthropogenic pressure, raising concerns about a possible transition of the Amazon from a carbon sink to a carbon source. This study examines the spatial and temporal variability of fire activity across Brazil, with a specific focus on the Brazilian Amazon, covering the period 2001–2022. The analysis is based on satellite-derived active fire data from NASA’s Fire Information for Resource Management System (FIRMS), using observations from the Moderate Resolu-tion Imaging Spectroradiometer (MODIS) and the Visible Infrared Imaging Radiometer Suite (VIIRS). Fire Radiative Power (FRP) is employed as a proxy for fire intensity and combustion dynamics. The VIIRS sensor, characterized by improved sensitivity to small and low-intensity fires, highlights the increase in fire activity observed after 2012. Significant peaks in fire activity were detected in 2004, 2005, 2007, and again after 2019. Statistical analyses reveal marked interannual variability and cyclical patterns in FRP, associated with fluctuations in drought conditions, precipitation regimes, land-use changes, human pressure and environmental policy measures. Overall, the results emphasize the importance of integrating multi-sensor satellite observations for long-term monitoring of fire regimes in Brazil, with particular relevance for the Amazon region.