Characterized by strong carbon storage and strong evaporation rates, the rain forest in Amazonia is under increasing pressure due to extreme weather situations (drought, flooding) and deforestation. Our modelling and field experiments will be based around the ATTO tower. One of the main goals of CloudRoots is to determine how the partitioning of the surface fluxes controls the transition between shallow and deep convection during the wet and dry period, and in years influenced by el Niño or la Niña. Special emphasis will be placed on studying the relevance of local evaporation and moisture recycling compared to long-range sources of moisture. In the specific case of the rain forest, the height of the canopy (~30 meters) requires detailed profiles of observations and high vertical and horizontal resolution.