A Wet Surprise: Drier Soils May Spur Rain
Drier soils are more likely to trigger storms than nearby wetter soils, a surprising new study finds.
These findings suggest global weather and climate models — which assume that dry soils mean dry weather — might currently be simulating an excessive number of droughts, the scientists behind the study said.
An international research team analyzed imagery from weather satellites that track storm clouds as they develop across the globe. When they matched up where new storms appeared on every continent save Antarctica alongside images of how wet the ground was, they discovered, to their surprise, that afternoon storms are more likely to rain down on parched soils.
"When we started this research we expected to find many areas of the world where afternoon rain was more likely over wetter soils, essentially because of the climate there," said researcher Chris Taylor, a meteorologist at the Natural Environment Research Council's Center for Ecology and Hydrology in England. "There have been a number of theoretical and atmospheric modeling studies along those lines, but an absence of observations thus far."
The researchers had been working in western Africa over the past decade and found that rain clouds there tended to brew in places where it had not rained in the previous few days. "We were surprised to see a similar pattern occurring in other regions of the world such as the U.S. and continental Europe," Taylor said in a statement. (The World's Weirdest Weather)
The findings, though, only hold true in certain climates and places.
The researchers emphasize "it's important to recognize that we are comparing storm statistics between nearby places with the same climate," Taylor told OurAmazingPlanet. "We are not saying that rain is more likely in the Sahara than the Amazon Basin."
Article continues at Our Amazing Planet
Parched Earth image via Shutterstock