WWII bombing raids sent shockwaves to edge of space, scientists say

Allied WW II bombing raids sent shockwaves to the edge of space, scientists say. Photo / News Limited

Bombing raids by Allied forces during the Second World War were so powerful they sent shockwaves through Earth's atmosphere to the edge of space, researchers have found.

The huge bombs dropped by Allied planes on European cities were big enough to weaken the electrified upper atmosphere – the ionosphere – above the UK, 1000km away.

Researchers studying records from the time found each raid released the energy of at least 300 lightning strikes, according to the Daily Mail.

RAF Attack Synthetic oil plant in Ruhr A Halifax bomber of RAF Bomber command fly's over the synthetic plant during a daylight attack. Photo / Getty Images

"The impact of these bombs way up in the Earth's atmosphere has never been realised until now, said Chris Scott, Professor of Space and Atmospheric Physics at the University of Reading.

"It is astonishing to see how the ripples caused by man-made explosions can affect the edge of space."

The discovery was made after researchers analysed daily records from the Radio Research Station at Ditton Park near Slough, where routine measurements of the ionosphere were taken from 1933 to 1996, in what is the "the longest continuous set of ionospheric measurements in the world" according to the study published in the journal Annales Geophysicae.

"Each raid released the energy of at least 300 lightning strikes," said Scott.

"The sheer power involved has allowed us to quantify how events on the Earth's surface can also affect the ionosphere."

The researchers decided to focus on major bombing raids of German cities by Allied forces and the Royal Air Force between 1943 and 1945, rather than the "London Blitz" earlier in the war.

This is because the blitz was ongoing from September 1940 to May 1941, which means the data would be harder to separate from other seasonal changes due to the sun that might affect the ionosphere.

Researchers studied the ionosphere response records around the time of 152 large Allied air raids in Europe and found the electron concentration significantly decreased due to the shockwaves caused by the bombs detonating near the Earth's surface.

This is thought to have heated the upper atmosphere, enhancing the loss of ionisation.

Detailed records of the Allied raids reveal their four-engine planes routinely carried much larger bombs than the German Luftwaffe's two-engine planes could.

Royal Air Force ground staff prepare to load a bomb onto a Handley Page Halifax. Photo / Getty Images

These included the "Grand Slam", which weighed up to 10 tonnes.

Scientists are using the findings to further understanding of how natural forces from below, like lightning, volcanic eruptions and earthquakes, affect Earth's upper atmosphere.

Professor Patrick Major, University of Reading historian and a co-author of the study, said: "Aircrew involved in the raids reported having their aircraft damaged by the bomb shockwaves, despite being above the recommended height.

"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.

"There were even rumours that wrapping wet towels around the face might save those in shelters from having their lungs collapsed by blast waves, which would leave victims otherwise externally untouched.'

"The unprecedented power of these attacks has proved useful for scientists to gauge the impact such events can have hundreds of kilometres above the Earth, in addition to the devastation they caused on the ground."