Análise da estrutura vertical do escoamento atmosférico durante ocorrência de eventos turbulentos intermitentes na camada limite noturna

Abstract

The objective of this study is to analyze the vertical structure of the intermittent turbulent events in the very stable boundary layer, as well the analysis and characterization of events originated near the surface that propagate upward. Therefore, it was used observational data from the FLOSSII experiment, together with the results of simulations using a numerical model that is able to reproduce the occurrence of turbulence bursts in the very stable boundary layer. The data have a total of 108 nights, from 20th of November 2002 to 02nd of April 2003, held in North Park south of Walden in the state of Colorado, in the United States. The experimental analysis showed that most of the events generated in the surface are very weak, not being able to connect the surface with the highest levels of the tower. Consistent with other studies, it was observed that the occurrence of events that propagates downward cause an increase in temperature, while events which propagate upward cause a cooling of the air near the surface. Another important result is much of the observed events that propagate upward are generated by wind acceleration due to drainge. Finally, it is shown that the events reproduced by the numerical model are caused by the shear increased and they are transported vertically by turbulent transport of energy, as observed in real world.