Raindrops are travelling farther than they used to before falling, according to new research. Warmer air, which can hold more water vapour, is altering not only the amount of rain but also its distribution.
Travis Aerenson and his colleagues at the University of Wyoming modelled atmospheric moisture movements in the US over more than three decades. Their findings indicate that in the southwestern and southern plains, atmospheric moisture travels 30 to 50 miles (50 to 80km) farther than it did 35 years ago, remaining airborne for an extra two to four hours before precipitating.
The research, published in Geophysical Research Letters, also shows an increase in evaporation from ocean surfaces and a decrease from land surfaces. These changes in atmospheric moisture pathways are expected to affect where and when precipitation occurs, with potential implications for land use.