Efeito da estrutura de torres micrometeorológicas nas medidas de turbulência atmosférica: Projeto ATTO

Abstract

Shadow effect have been cited as a source of uncertainty in atmospheric boundary layer studies due to mean wind deformation by the tower and its velocity attenuation in the wake region. To avoid this physical effect, most researchers discard data from the wake region. The presenting study analyzed the turbulent kinetic energy dissipation () and the inertial subrange behavior of turbulence spectra from two sonic anemometers at wake region of two 80 meters towers of distinct cross-section (square and triangular) in a dense rainforest (floresta ombrófila densa) in the Amazonian region. Spectral analysis results attempt to v and w components disturbance and an energy decay different from preview in Kolmogorov’s law at high frequency of inertial sub-range, both due wake turbulence production. Large peaks of  in the wake region of the order of 106 m2.s-3 attest that the rectangular tower deforms the mean wind flow much more, but the velocity distribution does not show differences between the two towers, indicating that weak winds are associated with topography and roughness in the ATTO. The amount of datatobediscardedreaches18%,ifisconsiderallthecontributionsfromthewakeregion, but the difference between the two towers in the amount of data discarded was not significant for the month studied.