  In this paper, we discuss the impact of a rain forest canopy on the
statistical characteristics of atmospheric turbulence. This issue is of
particular interest for understanding on how the Amazon terrestrial biosphere
interact with the atmosphere. For this, we used a probability density function
model of velocity and temperature differences based on Tsallis' non-extensive
thermostatistics. We compared theoretical results with experimental data
measured in a 66 m micrometeorological tower, during the wet-season campaign of
the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA).
Particularly, we investigated how the value of the entropic parameter is
affected when one moves into the canopy, or when one passes from day/unstable
to night/stable conditions. We show that this new approach provides interesting
insights on turbulence in a complex environment such as the Amazon forest.
