SMOKE POLLUTION REDUCES RAINFALL OVER AFRICA class

Scientists studying the world's tropical rainfall determined that a storm over a populated area in Africa may generate only half the rain as the same kind of storm over the ocean.

A main reason is smoke pollution, according to lead scientist Daniel Rosenfeld, a professor of meteorology at the Hebrew University of Jerusalem.
"The smoke and pollution particles, when going into the clouds, distribute the water into many small droplets. They are so small that they are very slow into combining into raindrops and other icy precipitation particles," Rosenfeld said.

Clouds formed in dirty air "produce as little as half of the rainfall from clouds of the same size in clean air," he said. Other factors contribute to the drought as well. For example, desert dust in the clouds makes them less efficient rain producers, according to the three-year study.
. . . .
The report observations come from data obtained from a satellite in low-Earth orbit, launched jointly by Japan and the United States in 1997. Called Tropical Rainfall Measuring Mission (TRMM), the orbiter scans and maps tropical storms with radar and microwave instruments from an altitude of 217 miles (350 km).