During the Cold War of the 1950s and 1960s, the US and Soviet Union carried out numerous nuclear bomb tests in remote areas, including the Nevada Desert and Pacific and Arctic islands. However, radioactive pollution was known to spread far away from the actual detonation sites. At the time, scientists set up research stations to study how this radioactivity affected atmospheric circulation patterns, but now a team from the University of Reading has re-analyzed this data to answer a new question: did the radioactivity affect rain?

The team examined records collected from 1962-1964 at a research station in Scotland. They found that days with higher radioactivity led to thicker clouds and more rainfall, even though this station was thousands of miles away from the bomb detonation sites. Radioactivity releases electric charge in the air, which the team believes can change the patterns of water droplet interactions in clouds. Scientists have long suspected that electric charge can have this effect on rainfall, but until now, it has been difficult to collect direct evidence of this phenomenon.

This work has important implications for geoengineering research. If rainfall can be influenced by electric charge, as this team seems to have shown, then technology could be developed based on this idea to address crises like droughts or floods. Much more research would have to be done first, but this work still opens the door to a promising new avenue.

Managing Correspondent: Isabella Grabski

Press Article: “Cold War nuke tests changed rainfall: study,” Phys.org.

Image Credit: “White clouds, black clouds” by jgbarah is licensed under CC BY-SA 2.0

Scientific Article: “Precipitation Modification by Ionization,” Physical Review Letters.