Simulation of an orographic gravity wave above the Amazon rainforest and its influence on gases transport near the surface

Abstract

The influence of the topography at the ATTO site (Amazon Tall Tower Observatory) in the formation of Gravity Waves (GW) was investigated in this work. The role of these waves in gas transport on different heights in the nocturnal boundary layer, was also investigated. For this, were analyzed: experimental data of wind speed, temperature, humidity and CO2 to identify the GW. Furthermore satellite images, ECMWF ERA5 (European Center for Medium-Range Weather Forecasts) reanalysis, and numerical simulations from the mesoscale JULES-CCATT-BRAMS model (Brazilian Regional Atmospheric Modeling System) version 5.3 were used to perform GW simulations. The simulations involved two configurations (Control-With Topography and No Topography). The sattelite images made it clear that the GW was not associated with convective activities. The simulations showed clear ondulatory signs in air temperature, vertical component of the wind, and gases like CO and O3. Moreover, they also reveal that the wave originated by the presence of the local topography and this orograph gravity wave had and important role in the transport of gases above the ATTO site.