Nuclear Bomb Testing During the Cold War Changed Weather Systems Thousands of Miles Away

Atomic bomb tests during the Cold War could cause rainfall for at least two years, changing the pattern of rainfall thousands of miles away from the site of the explosion. Nearly half a century ago, the post-World War II tensions escalated as the post-World War II world powers competed to develop nuclear weapons.

During the Cold War in the 1950s and 1960s, the United States and the Soviet Union conducted nuclear tests in remote areas of the world, from the South Pacific Ocean to the American Southwest.  Most of these test sites today carry spots and some are even radioactive, but what happens at the nuclear site is not there. Between 1962 and 1964, radioactive pollutants spread throughout the atmosphere, ionizing the air and releasing electrical charges that alter rainfall variability.

Researchers at the University of Reading in the United Kingdom determined how the electric charges emitted by radiation from experimental explosions affected the rainclouds at that time by reviewing historical records from two meteorological stations in the United Kingdom between 1962 and 1964. Weather records are then compared with cross-references to bomb test data with charges produced by high and low radioactivity.

The researchers found that the clouds were visibly thicker and received an average of 24 percent more rainfall per day with more radioactivity, the Physical Review wrote in the Letters Journal. Electrical observations show that the extra atmospheric ionization caused by radioactivity during that time “increased the current in the global circuit” and, in fact, “the stratospheric radioactivity spread so far in the Northern Hemisphere that similar electrical changes are widely expected.”

Professor Giles Harrison, lead author, and Professor of Atmospheric Physics at the University of Reading said in a statement. “By studying the radioactivity released from Cold War weapons tests, scientists learned about the patterns of atmospheric conduction at that time. We have now reused this information to test the effects of precipitation.” “The politically charged environment of the Cold War led to the nuclear arms race and global concern. Decades later, we have found the silver lining of clouds around the world with a unique way of studying how global cloud rain affects rain.”

It is basically thought that electric charge clouds can change how water droplets collide and condense, which can affect their size and precipitation. Depending on a variety of factors, including the rate of precipitation density produced in the clouds and how quickly water droplets are able to gain mass, these make them heavy enough to fall on the surface. Radioactivity can affect the charge of these droplets using electrical energy to correct and affect clouds and their respective precipitation. Scientists have come to the conclusion that their findings for cloud-related geological research could be helpful in determining how electric charges may play a role in effectively affecting rainfall in drought relief or flood prevention.