Can African dust help cool the Earth?
Click here to expand. Dust in the Bodele as seen from the Terra satellite.
DB: This is Earth & Sky. In 2005, scientists from the United Kingdom camped out in northern Africa to study the dustiest place on Earth.
JB: Called the Bodele depression, it’s a dry lake bed located in the African country of Chad. The lake bed is covered in diatomite, the remains of algae that lived and died in the lake. Winds carrying sand from the Sahara Desert are funnelled into the depression at high speeds through a gap between two mountain ranges. As the sand hits the diatomite, it breaks it into a fine powder that’s easily swept up by the wind.
DB: Large plumes of dust from the Bodele depression travel over the Atlantic Ocean. The dust shades the ocean and cools it. Atlantic hurricanes are born over the warm waters near Africa, but this cooling effect of Bodele dust can stop them from forming.
JB: The nutrients in the dust also fertilize algae in the ocean. This makes it able to absorb large amounts of carbon. Charlie Bristow, a sedimentologist at the University of London, was one of seven scientists on the Bodele expedition.
Charlie Bristow: This is potentially a huge sink for carbon in the Atlantic. Algae growing in the Atlantic are going to be absorbing carbon dioxide from the atmosphere. That’s going to be removing carbon dioxide from the atmosphere and that’s a good thing in terms of global warming.
DB: Our thanks today to NASA: explore, discover, understand. We’re Block and Byrd for Earth & Sky.
See more images of the Bodele NASA.
Our thanks to:
Dr. Charlie Bristow
Senior Lecturer
School of Earth Sciences
Birkbeck College
University of London
Additional Teacher Resources
NASA Earth Observatory: Bodele Depression Dust Feeds Amazon
Though wind-scoured and virtually barren, the southern Sahara Desert turns out to be a surprising sustainer of life an ocean away-in South America’s Amazon Rainforest. By studying NASA satellite data of the spread of dust across the globe, scientists discovered that more than half of the mineral dust that fertilizes the Amazon soil comes from a single spot in the southern Sahara, a large mountain-rimmed valley called the Bodele Depression.
NASA: Hurricane Web Page
NASA’s primary hurricane page, this site provides several resources including the latest hurricane news, multimedia resources, and links to more information.
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