By Romao, M. and Pires, L. B. M.
Atlanta, December 29, 2017.
In the silence of the early hours of the morning, just after sunrise, when the forest begins to awaken, Aru arises. Aru is the name given to the strong fog or fog that forms in the Amazon. This mist leaves the forest with a mysterious and enigmatic air and is part of the local legends and myths. For the indigenous peoples of the upper Rio Negro, the Aru is a gift from the Gods. “It is a wind that lives in the waterfalls and that leaves, at a certain time of the year, to settle the forest, nourishing it and making it fruitful.” When the Aru travels downstream or upstream, the animals accompany it, facilitating indigenous hunting. It is at this time that the peoples of the Upper Rio Negro prepare the feasts of the Dabucuri which is an ancient ceremony that takes place in the region of the Upper Rio Negro. During the ceremony there are exchanges of knowledge that involves songs, music, dance, food, food, stories, ornaments, rites of passage, moments of social political alliance and marriage arrangements.
Although Aru is a common meteorological phenomenon in the jungle, and apparently generally harmless, it can be very dangerous for anyone who flies or navigates in the Amazon. Flying under Aru conditions is complicated because, although it is low in altitude, it is dense which puts flight safety at risk.
The formation of Aru closely resembles radiation fog. The strong humidity inside the Amazon forest, in the range between soil and tree canopies and the temperature of this range, which is usually smaller than the atmospheric layer just above; causes a kind of radiation fog.
Condensation due to evapotranspiration from the surrounding environment occurs below the tree canopies and gradually ascends, due to the general warming of the morning.. The Aru begins weak and tenuous but gradually fills up forming an immense white carpet above the tree canopies, which hides the forest from the eyes of anyone who is flying above.
The presence of the Aru is also indicative of the quality of the Amazonian ecosystem; as deforestation increases, someday the Aru may cease to exist, and with it will go all the mysteries that the Amazon preserves. Where Aru is, there is forest and abundance, as the Indians of the Upper Rio Negro know well.
References:
http://www.pos.uea.edu.br/data/area/titulado/download/30-15.pdf