São Paulo – The climate in Brazil and in neighbouring countries is threatened by deforestation of the Amazon, mainly due to the rain cycle. This is one of the conclusions of the Flying Rivers Project, which has the sponsorship of Petrobras and of the National Water Agency (ANA) and was disclosed this week by the state-owned oil company.
According to project figures, there is great recirculation of water from the surface to the atmosphere, caused by the transpiration of plants that make up the forest, which contributes to the high levels of precipitation in the Amazon, that may exceed 2,400 mm/year. Due to this, the destruction of the forest causes alterations that are still difficult to quantify.
The project coordinator, Gerard Moss, who has already promoted 12 trips flying over Brazil in a single-engine aircraft, explained that a large tree sends about 300 litres of water into the atmosphere each day and its removal does not only affect the Amazon, but all other regions to which the water is transported by the wind. "In Brazil, we have lost around 600,000 square kilometres of forest area over the last 30 years. We cannot yet precisely measure the impact on the climate," said the researcher in a press statement disclosed by Petrobras.
The information collected by the team is aimed at showing to what extent the deforestation of the Amazon may affect the climate of Brazil and how degradation may alter the cycle of distribution and circulation of water in nature. "The objective is to better understand the route followed by these true flying rivers, which travel over people’s heads and may have a volume greater than that of all the rivers of the midwest, southeast and south [of Brazil]," said Gerard, who in his last expedition collected around 500 samples of water vapour from different layers of the atmosphere, between 500 and 2,000 metres above the sea level.
To collect the samples, there is an external collector on his aircraft that draws in some of the air and guides it into a glass jar, which is chilled in dry ice at minus 80ºC, causing condensation of the humidity into a drop in the tube. The samples are analysed at the Agricultural Nuclear Energy Centre (Cena), in Piracicaba, in the interior of the state of São Paulo. Based on the properties of this drop of water, the origin, dynamics and movement of the water transported by the wind are defined.
Studies by the scientific coordinator of the project, Enéas Salati, show that 44% of the water vapour flow that penetrates the Amazon region coming from the Atlantic Ocean conditions the climate of South America and reaches regions in the South, Southeast and Midwest. This discovery was fundamental for the elaboration of the project, which is aimed at bringing to the population of great urban centres information related to the environment.
*Translated by Mark Ament
