Climate satellites helped environmentalists first charge the amount of dirt particles from the Sahara desert, which fly crossways the Atlantic and into the soil of the Amazon forest, enriching them with micronutrients, according to a paper published in the journal Geophysical Research Letters.
Today, climatologists and environmentalists trust that the main lungs of the planet, the Amazon rainforests are not totally self-sufficient. For their normal operation needs a stable supply of phosphorus, potassium and many other nutrients,
which are constantly washed out of the soil by rain and rivers in the open ocean. They are considered to be the main source of the Sahara desert, whose sands are regularly transported sub-equatorial winds in South America.
Explains lead author, Hongbin Yu from the University of Maryland (USA) today, scientists have been actively interested in the mass of sand and nutrients that are transported from Africa to the Amazon, since this information is critical to understanding how forests South America will respond to climate modify.
For model, if the wind is transported quite modest amount of sand, then the increase in the quantity of carbon dioxide in the atmosphere will not lead to the widening of the Amazon forest, which for this not to be missed nutrients. As a result, global warming will come earlier than you expect today climatologists.
Based on these ideas, Yu and his colleagues initial tried to exactly measure the mass of intercontinental sand, using the tools of climate satellite CALIPSO, launched into orbit jointly by NASA and the French agency CNES in 2006. In adding, environmentalists have made numerous expeditions to the Amazon and the Caribbean, where they collected dust samples and evaluated its chemical composition.
In total, scientists have spent about seven years aged, watching streams of dust over the Atlantic before they decided to publish the findings. It has been observed every year wind and diverse climatic phenomena rises into the air and transferred to the side of the Amazon, on average 182 million tons of sand and dust, about 15% of which ends up in the ocean on the way to South America.
According to calculations of the authors, in those 130 million tonnes of Saharan sand, which are deposited in the Amazonian forest, contains approximately 22 thousand tons of phosphorus. Approximately the same amount of nutrients leached from the soil yearly Amazon rivers that helps give details how to survive tropical lungs of the Earth.
As acknowledged by the scientists, the seven years of observing the flow of dust is not sufficient to capture the long-term trends and to understand how climate change will influence the Amazon. Even in those seven years, rates have fluctuated greatly, and the amount transferred dust over the years sometimes differs by almost a factor of two.
The reason for such fluctuations are believed environmentalists were alternating periods of drought and the rainy season in the Sahel, a buffer zone among the Sahara and the rest of Africa, but to test this hypothesis will take another few years, if not decades, observations, the authors conclude the object.