Simulações dos grandes vórtices (LES-PALM): diferentes estratégias de aquecimento de um dossel florestal amazônico

Abstract

In this work, the Large Eddy Simulation (LES-PALM) was used to simulate turbulent flow within and above a canopy forest with similar characteristics to those found at the experimen- tal site of the ATTO project (Amazon Tall Tower Observatory), located in the central Amazon region. LES-PALM simulations allow a detailed analysis of turbulent flow properties, as well as the performance of virtual experiments for different scenarios, such as different roughness, topography, etc. Furthermore, LES simulations allow a better three-dimensional understand- ing of turbulent flow, which would be impossible through experimental data from isolated micrometeorological towers. The objective of this study was to investigate the components of the radiation and energy balance, in addition to the profiles of different statistical moments of turbulence, for two simulations with different parameterizations of canopy heating: i) in the first of them, a heat source was inserted at the top of the canopy. The sensible heat flux used to initialize the simulation was similar to the values observed experimentally and, ii) in the second simulation, the RTM radiation module was used as a canopy heating source. To validate the simulations, experimental data profiles of radiation, wind temperature, humidity, and turbulent flows collected in the micrometeorological towers of the ATTO project were used. As a main result, it was observed that the simulation where the RTM radiation module was used produced much more realistic simulations than those where a heating source was introduced at the top of the canopy. Obviously, the RTM module still needs some refinements for the Amazon region, however, it is believed that the results shown in this work will help in better LES simulation strategies for the Amazon forest.