How The World's Largest Hot Desert Fertilizes The Amazon

The world's largest hot desert fertilizes the world's largest rainforest. That's according to a study published Tuesday in "Geophysical Research Letters," which examined the quantity and chemical composition of dust swept by strong winds from the Sahara to the Amazon every year. Researchers found that much of the rainforest's phosphorous -- a critical element in plant growth -- originates in Chad. Using data provided by NASA's "CALIPSO" satellite, researchers determined 27.7 million tons (or 104,980 semi trucks worth) of Saharan dust lands in the Amazon on a yearly basis, making it the largest transport of dust on the planet. Lead author Hongbin Yu, an atmospheric scientist at the University of Maryland who works at NASA's Goddard Space Flight Center, told NASA phosphorus comprises 22,000 tons of that dust, which, coincidentally, is similar to the amount of phosphorus leached from the soil every year by rain and flooding. The study authors speculate African dust has thus played an important role in feeding the Amazon critical nutrients "on time scales of decades to centuries." "This is a small world," Yu told NASA, "and we're all connected together."