Each raid released the energy of 300 lightning strikes, and caused man-made ripples right to the “edge of space”.
Allied bombing in 1942 reduced cities like Dresden and Hamburg to ruins, but its effects extended right up to the ionosphere, which extends from an altitude of 50km (31 miles) to 1,000km (620miles).
The ionosphere is electrified by radiation from the sun and space, but during the bombing raids the electrical charge it carried was significantly weakened, scientists have discovered.
A team from the University of Reading uncovered this phenomenon when they compared detailed records of raids with records from British wartime scientists investigating the upper atmosphere.
Chris Scott, Professor of Space and Atmospheric Physics at the University of Reading said: “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.”
Between 1943 and 1945, scientists working at the Radio Research Centre at Ditton Park, near Slough, fired shortwave radio pulses to 100-300km above the earth’s surface.
They worked out the height and electrical density of the ionosphere from the echoes of these radio signals bouncing back.
What they did not realise is what their findings really reveal about the impacts of the war on these layers of ionosphere.
Professor Scott said: “Work at Slough was routinely analysing the height and intensity of these layers to understand how they vary, but what they didn’t realise at the time was that they actually contained the signatures of the war itself.
“The images of neighbourhoods across Europe reduced to rubble due to war time air raids are a lasting reminder of the destruction that can be caused by man-made explosions.
“But the impact of these bombs way up in the Earth’s atmosphere has never been realised until now.”
The bombs dropped on Germany by allied raids could weigh up to 10 tonnes and as much as 2,000 tonnes of explosives could be dropped in a single night.
The research, published in the European Geosciences Union journal Annales Geophysicae, has produced yet more evidence of how man’s activities interact with the atmosphere.
The ionosphere is influenced by solar activity, thunderstorms and volcanic eruptions and its electrical properties affect radio communication and GPS.
University of Reading historian Professor Patrick Major said: “Aircrew involved in the raids reported having their airraft damaged by the bomb shock waves, 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 flown off their hinges.
“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.”