Agricultural Fires and Drought: Human-Set Fires in Africa Altering Rain

A recent NASA study has confirmed that agricultural fires set to clear fields and improve soil in North Africa are affecting the region's rainfall in the dry season -- in another example of human behavior unintentionally modifying weather. The researchers recently published their findings in the journal Geophysical Research Letters.

The researchers at NASA's Jet Propulsion Laboratory looked at satellite images and analyzed how aerosols, or microscopic smoke particles, affect cloud formation and rainfall. They examined fires south of the Sahara Desert and north of the equator, and they looked at that area because about half of fires on Earth annually take place in Africa, a release said.

The studied images were from three NASA satellites that cross the region at varying times of day. Weather reports added to the data. By examining images taken from 2006 to 2010, they determined that less cloud cover built up throughout the day in smoky scenes than in those without smoke, in otherwise statistically identical weather conditions, according to the release.

"Less clouds and rainfall dry out the land and make it easier for farmers to ignite more fires, which data show they probably do," JPL's Michael Tosca said in the release. The additional burning could lead to regional climate warming over time, he said.

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