Evaporation from Amazonian rainforest

Sample measurements of dry-canopy evaporation from three intensive field campaigns and continuous measurements of rainfall interception loss are used to calibrate a micrometeorological model of evaporation from the forest canopy. Over the whole study period, approximately 10% of rainfall was intercepted by the forest canopy, and this accounted for 20-25% of the evaporation. The remainder occurred as transpiration from the trees. Over this same period, about one half of the incoming precipitation is returned to the atmosphere as evaporation, a process which requires 90% of the radiant energy input. These data provide a basis for assessing the likely consequences of Amazonian deforestation on surface water and energy balances. -from Author