It is well known that during the 1950s and 1960s, in the world environment stressed by the Cold War, countries such as the United States and the Soviet Union carried out tests with nuclear weapons as a way to demonstrate their power, which resulted, among others things, to the appearance of radioactive fallout over certain regions. The charged particles emitted during radioactive decay have the ability to collide with the atoms and molecules around them, giving rise to new particles that have even more charge. And these can engulf dust, soot, or water droplets found in the atmosphere, causing them to become thick enough to fall to the ground in the form of rain. Radioactive fallout could have very harmful effects on the atmosphere, land and its inhabitants, causing irrevocable damage. However, one of the unexpected effects of these tests could have gone further, turning into something very positive.
And it seems that the radioactivity emitted by these nuclear bombs would have caused an increase in rainfall , not only in those places where these tests were carried out, but also causing greater rainfall in areas located thousands of kilometers away . Although the tests were conducted in remote locations, such as the Nevada desert of the United States, or on some islands in the Pacific and the Arctic, radioactive pollution spreads very easily through the atmosphere. And, in turn, radioactivity ionizes the air, releasing an electrical charge.
This is indicated by a recent study carried out by a group of scientists from the University of Reading and published in Physical Review Letters , who for their finding focused on studying the history of rainfall that had taken place between 1962 and 1964 on a small island to the north from Scotland . The place was chosen by the researchers for being an area probably little affected by pollution, a factor that also influences when clouds form and precipitations are triggered.
Thus, they compared the days in which the greatest radioactive load had been concentrated with those that had collected a lesser one, to see if the volume of rainfall had been greater in the former than in the latter. And, indeed, they discovered that it was: there was, on average, 24% more rains during the days with more radioactivity throughout the period of time studied.
Prior to this retrospective study, it was long thought that electrical charge influenced the way that the water droplets that make up clouds collide and combine , potentially affecting their droplet size and rain, but there were it has been very difficult to make such an observation directly in the atmosphere.
“The politicized atmosphere of the Cold War led to a nuclear arms race and a global sense of anxiety, but decades later it has shown a silver lining, giving us a unique way to study how electrical charge affects rain,” celebrates Giles Harrison , lead scientist for the research.
Because the best thing is that the results obtained by the study could be very useful when carrying out investigations in the field of geoengineering related to clouds, since the way in which the electrical charge affects the rain would serve to address new solutions to droughts or floods without having to resort to the use of chemicals. Additionally, Harrison suggests that it could also help astronomers better understand weather patterns on other planets such as Jupiter and Neptune, whose atmospheres are filled with charged particles generated by lightning or cosmic ray impacts.
