Cell phone towers monitor African rains

Distorted cell phone signals could help track the rains down in Africa.

While not always noticeable, cell phones get worse reception during rainstorms. Raindrops garble specific frequencies in radio signals, an effect compensated for by cell phone companies. Scientists realized these tainted transmissions could be used to reconstruct rain patterns near cell phone towers and since 2006 have successfully implemented the technique in developed countries such as the United States. Some have proposed that the method’s most important use could be in Africa, where weather-monitoring infrastructure has fallen into disrepair. Tracking weather has become particularly important in the face of climate change, which can exacerbate rain-related hazards such as floods and droughts.

Geoscientist Ali Doumounia of the University of Ouagadougou in Burkina Faso and colleagues partnered with a telecommunications company to conduct the first cell phone tower rainfall monitoring in West Africa. The team crunched data transmitted during the 2012 monsoon season between two transmission towers separated by 29 kilometers. The researchers report July 14 in Geophysical Research Letters that they detected 95 percent of rainy days and measured rainfall as well as weather satellites did, or better.

As Africa’s wireless networks expand coverage, the team hopes the technique can provide cheap rainfall tracking.