Many thanks to a number of SWLing Post contributors including, Mike, Dan, Ron and Bob who all shared this article from the BBC World Service:
The bombs used by Allied forces during World War II were so large, they weakened the Earth’s upper atmosphere.
The air raids turned towns to rubble and ash, but now new research shows shockwaves could be felt up to 1,000 km above the UK.
Chris Scott, from the University of Reading said: “I was absolutely astonished [when I found out].
“Each raid released the energy of at least 300 lightning strikes.”
It’s now hoped the research will give us a better understanding of how natural forces such as lightning, volcanic eruptions and earthquakes can affect Earth’s upper atmosphere.
[…]But Chris Scott admits “these were very temporary effects which heated the atmosphere very slightly.”
[…]Chris Scott said: “This [research] is really important if we’re going to understand the ionosphere as a whole.
“We know the ionosphere is controlled by solar activity but it varies much more than can currently be explained.”[…]