Discrepancies in precipitation trends between observational and reanalysis datasets in the Amazon Basin

The Amazon rainforest is a region of global importance as it accounts for 10% of terrestrial biodiversity and stores at least 10 years’ worth of global anthropogenic carbon dioxide () emissions. However, the rainforest is currently under tremendous pressure from deforestation and the impacts of climate change, leading to rainforest degradation and perturbations of the regional carbon and water cycles. Using data sets from various sources, we produce spatial and temporal analyses of precipitation for the Amazon Basin from 1980 to 2022. Results demonstrate substantial seasonal and regional variations across the Amazon Basin, indicating that while some regions are experiencing increasing trends in precipitation, others are undergoing declines. These trends are not consistent among available datasets, with substantial differences between observational, reanalysis, and climate model data. For example, precipitation data from reanalyses for 1980–2022 reveal significant drying patterns in the southern and central Amazon during the dry season, which are not present in the observational datasets.