How much dust blows across the Sahara Desert?
It sounds like a philosophical musing or the start of an old proverb. But it’s a question that now has a precise answer, thanks to data collected from 2007 to 2013 by NASA’s CALIPSO satellite.
Scientists studied data collected by CALIPSO, which was launched in 2006 to study clouds and aerosols and gauge how they affect weather systems, and found that on average, a stunning 182 million tons of dust each year are blown past the western coast of Africa that bounds the Sahara. As the NASA Earth Science News Team points out, that’s enough dust to fill about 690,000 semi trucks. The dust then crosses the Atlantic ocean, where 27.7 million tons of it settle in the Amazon basin.
The NASA Scientific Visualization Studio put together an excellent visualization of this geo-phenomenon: