PRECIPITATION RECYCLING IN THE AMAZON: A REVIEW STUDY

This paper constitutes a historical perspective in the evolution of the knowledge on precipitation recycling and provides a critical view on the current state-of-the-art. The main sources of moisture for Amazon rainfall and the transport of water vapor over South America are described. The recycling mechanism quantification is an indicator of the importance of the land-surface processes and climate to the hydrological cycle, as well as climate sensitivity associated to changes in these processes. The climatological aspects of the recycling precipitation over South America shows that the advective contribution is more important for the precipitation over the Amazon basin and Brazil's Northeast, while in the Central-South region the local contribution plays an important role in the precipitation. It is estimated that the precipitation recycling in Amazon basin is 20-35%. Over the Amazon, advection of moisture dominates the supply of atmospheric water vapor over much of the river basin but local evaporation is much more prominent over the southern region. Although the precipitation recycling studies have produced new information concerning the interaction between the land-surface processes and hydrological cycle, the effects of global climate change in this mechanism are not yet fully understood.

Amazon Basin; precipitation recycling; moisture flux; water budget; biosphere-atmosphere interaction.