Bombs from WW2 had a rippling effect on the edge of space

Bombs from WW2 had a rippling effect on the edge of space
Almost 80 years after, impacts from the brutal bombings of World War 2 are still felt around the world.

The aerial raids didn't just have stains through generations of families. Christopher Scott (the space and atmospheric physicist at the Uni or Reading in the UK), recently discovered that the bombs had slightly effected the edge of space.

By searching through the archived data, Scott discovered that the shock waves from the bombs had briefly weakened the ionosphere, which is the outermost layer of Earth's atmosphere.

From Lightning to bombs

Somewhere between 50 and 375 miles (that's 80 and 600 kilometers) above sea level, the ionosphere is where auroras originate and where the ISS cruises. Atoms of gas in this layer get a little excited by any solar radiation, creating electrically charged ions! The density and altitude of electrons, the negatively charged particles, in the ionosphere can start up some volatility.

"The ionosphere is far more variable than can be explained by solar activity," Scott told in a statement.

Scott's previous research has shown us that lightning could enhance the ionosphere. He was intrigued to find out if it was due to the explosive energy of lightning of its electrical charge. So, he set out to look out for well documented explosions on the ground, and to compare the historical data with archival data from the Radio Research Center in Slough, where scientists had measured the density ionosphere using radio pulses sent over a range of shortwave frequencies.

Scott originally said he intended to look at the effects of the London Blitz, but little information survives about the timing and munitions used for these raids. As an alternative, Scott's colleague Patrick Major, a historian at the University of Reading, provided a database on the bombing of Berlin between 1943 and 1944 and directed Scott to other data sets about Allied air raids over Europe.

Shock Waves

Each raid released the energy of at least 300 lightning strikes, Scott said, and historical accounts from the ground attest to the far-reaching power of bombs like the 22,000-lb. (10,000 kilogram) British "Grand Slam."

"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," Major said in a news release.

When the researchers looked at the ionosphere-response records around the time of 152 large Allied air raids in Europe, they found that the electron concentration significantly decreased due to the shock waves from the bombs. The findings were published today (Sept. 25) in the journal Annales Geophysicae.

"I was able to see an effect in the U.K. ionospheric records from bombing over 1,000 km [620 miles] away," Scott said. "I was surprised by that."


Ingo Mueller-Wodarg, a planetary scientist at Imperial College London who was not involved in the study, said the research is "a neat demonstration of how the ionosphere is affected by activity on the ground, despite being many tens to hundreds of kilometers above the ground."

The effects of the shock waves would be temporary, Scott said, lasting under a day. "The ionosphere is largely controlled by solar radiation," he told Live Science. "The bombing represents a small impact by comparison."

Scott added that the ionosphere weakening may have affected the efficiency of shortwave radio communication, which relied on the ionosphere to reflect the signals over long distances.


More modern technologies, such as GPS, are affected by disturbances in the ionosphere. Another study published earlier this year found that the massive shock wave from a 2017 launch of a SpaceX Falcon 9 rocket created a temporary hole in the ionosphere, which may have disrupted navigation signals for an hour or two afterward.

Next Steps

Mueller-Wodarg noted that there has long been speculation on whether earthquakes affect the ionosphere, with mixed results. "This study lends strong support to the suggestion that events on the ground which generate any kind of shock wave or strong impulses should be able to be felt in the ionosphere," Mueller-Wodargtold Live Science.

Scott said he also wants to find out if thunderstorms, volcanoes and earthquakes can be detected using similar methods.

He is also currently digitizing earlier U.K. ionospheric data with the intention to put this information online, so that volunteers can help identify more effects on the ionosphere. Doing so might help Scott understand why lightning has an impact on the ionosphere.


"The ionospheric layer that we saw responding to the bombing was much higher than the one used in the lightning study, as it was the only one for which digital data currently exist," Scott said. "This is one of the reasons why I want to digitize the ionospheric data, so that we can look to see if the layer that was enhanced by lightning is also enhanced by the bombing. Only then can we say for sure if the lightning effect is due to shock waves or an electrical current —or both."