WWII bombs sent shockwaves to the edge of space

Sept. 26 (UPI) — The edge of space is more than 62 miles away, but what happens on Earth’s surface can effect even the uppermost layers of Earth’s atmosphere.

According to a new study published this week in the journal Annales Geophysicae, Allied bombing raids during the Second World War were powerful enough to send shockwaves to the edge of space.

“The images of neighborhoods across Europe reduced to rubble due to wartime air raids are a lasting reminder of the destruction that can be caused by man-made explosions,” Chris Scott, professor of space and atmospheric physics at the University of Reading in England, said in a news release. “But the impact of these bombs way up in the Earth’s atmosphere has never been realized until now.”

Previous studies have revealed the effects of lightning strikes and volcanic activity on the upper layers of Earth’s atmosphere, including the ionosphere. The latest findings suggest exploding bombs can also impact atmospheric dynamics at the edge of space.

“It is astonishing to see how the ripples caused by man-made explosions can affect the edge of space. Each raid released the energy of at least 300 lightning strikes,” Scott said. “The sheer power involved has allowed us to quantify how events on the Earth’s surface can also affect the ionosphere.”

From 1924 to 1979, scientists at the Radio Research Station in Slough, England, regularly aimed shortwave radio pulses at the atmosphere. The rebounding radio signals helped scientists characterize the changing height and ionization levels in the upper layers of the atmosphere.

For the latest study, Reading researchers analyzed the radio signals collected between 1943 and 1945. Scientists found marked decreases in the ionosphere’s electron concentration corresponding to 152 large Allied air raids in Europe during the three-year period.

The analysis confirmed Allied bombs were significantly more powerful than those dropped by the German Luftwaffe. The Allied forces’ “Grand Slam” raids included bombs weighing more than 10 tons.

“Aircrew involved in the raids reported having their aircraft damaged by the bomb shockwaves, despite being above the recommended height,” said Patrick Major, a professor of history at Reading. “Residents under the bombs would routinely recall being thrown through the air by the pressure waves of air mines exploding, and window casements and doors would be blown off their hinges.”

In the wake of the novel work, study authors have requested for the assistance of citizen scientists in the effort to digitize early atmospheric data. Scientists hope to look for links between smaller bombing raids and changes in the ionosphere in order to determine the minimum level of explosive energy required to send shockwaves to the edge of space.

The behavior of the ionosphere can affect modern communications technologies like GPS. By better characterizing the impact of surface-level phenomena on the upper atmosphere, scientists can develop best practices to better protect communication systems.