A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

Modeling the fine-scale turbulence within and above an Amazon forestusing Tsallis’ generalized thermostatistics. I. Wind velocityMaurício J. A. Bolzan 1,3,* , Fernando M. Ramos 2 , Leonardo D. A. Sá 1 , Camilo RodriguesNeto 2 , Reinaldo R. Rosa 21. Laboratório Associado de Meteorologia e Oceanografia, Centro de Previsão de Tempo eEstudos Climáticos, Instituto Nacional de Pesquisas Espaciais, São José dos Campos,Brazil2. Laboratório Associado de Computação e Matemática Aplicada, Instituto Nacional dePesquisas Espaciais, São José dos Campos, Brazil3. Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dosCampos, BrazilAbstract: Modelling of the fine-scale for vertical wind velocity component above andwithin Amazonian forest has been performed using Tsallis' generalized thermostatisticstheory (GTS). We show that such a theory provides an accurate framework for modelingthe statistical behavior of the inertial subrange above and below the canopy. For this, wecompared the experimental probability density functions (PDFs) with the theoreticallypredicted ones. The data were measured in March 1999, during the wet-season of the LargeScale Biosphere Atmosphere Experiment in Amazonia (LBA), in southwestern part ofAmazonia region. Measurements were made simultaneously at different heights in a 60meters micrometeorological tower located in the Biological Reserve of Jaru (10 o 04´ S, 61 o56´ W), Brazil. The fast response wind speed measurements, sampled at 60 Hz rate, weremade using Campbell three-dimensional sonic anemometers at the heights of 66 m (abovethe canopy) and 21 m (below the canopy). Above the canopy forest, results showed goodagreement between experimental data and the Tsallis´ generalized thermostatistics theory.For below canopy data, the agreement between the experimental and theoretical PDFs wasfairly good, but some distortion was observed. This is probably due to some peculiarcharacteristics of turbulent momentum transfer process inside the forest crown. Discussionis presented to explain these results; conclusions regarding the absence of “universalscaling” in the inertial subrange are also presented in the context of the entropic parameterof Tsallis’ theory.____________________* Corresponding author.E-mail address: bolzan@univap.br