Tech – Metro | Mysterious and beautiful ‘gravity waves’ seen surging through Earth’s atmosphere

Gravitational waves are ripples in space-time produced by the collision of two black holes or dramatic events such as a supernova explosion.

So you may be a little concerned to hear that gravity waves have been spotted rippling through Earth's atmosphere.

But even though these two types of waves sound very similar, they are actually totally different. Which is nice, because if two black holes crashed into each other near our planet, humanity would probably be wiped out.

A gravity wave takes place within the atmosphere of a planet, rather than out in deep space.

They are waves generated within a fluid after it is disturbed in some way. As the fluid settles back into equilibrium under the force of gravity, it will sometimes move back and forth. This oscillation generates a wave.

Gravity waves can also be generated near the 'interface' between water and air, so can be found on the surface of seas as well as high up in the air.

They are normally invisible but can be seen in the sky when cloud forms along a wave's edge.

Atmospheric gravity waves over the Coral Sea this morning. pic.twitter.com/hVKTbw12Z0

— Andrew Miskelly (@andrewmiskelly) October 9, 2019

More atmospheric gravity waves. Triggered, in this case, by outflow from isolated thunderstorms over eastern NSW this afternoon. pic.twitter.com/tE5OQDouHB

— Andrew Miskelly (@andrewmiskelly) October 24, 2019

The phenomenon was demonstrated in a tweet written by Andrew Miskelly, a developer at an Australian meteorological company called Weather Zone.

He wrote: 'Waves cause the air to rise and sink, cooling and warming its water vapour and making upper water vapour temperature an effective means of visualisation.

'In some cases, cloud forms on the crests.'

Miskelly shared several stunning illustrations of the waves, including a view of waves shooting from a thunderstorm.

'There was a big thunderstorm over the north-west of Western Australia and the disturbance, in this case, was the cold air falling out of the thunderstorm and into the warmer air near the surface,'  Adam Morgan of the Australian Bureau of Meteorology told the ABC.

'The difference in density there causes the disturbance and then the gravity wave can travel out as the cold air spreads out. The disturbance will exist until everything rebalances itself, that's why they can travel a long way.'

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