Satellites have captured several groups of atmospheric gravity wave clouds off the northwest coast of Australia on Tuesday.

The satellite images below show thin bands of cloud moving over the Indian Ocean to the northwest of Australia on Tuesday, August 8, 2023.

These unusual clouds are being caused by a phenomenon called atmospheric gravity waves. Just like the ripples that form when a stone is thrown into a pond, atmospheric gravity waves occur when a disturbance – such as a thunderstorm – causes waves to form in the sky.

Atmospheric gravity waves are vertical waves that cause air to rise and fall in the sky. Because the rising air becomes cooler, the top sections of the gravity waves can produce bands of cloud via condensation, while the regions of sinking air often produce clear air in between the cloud bands. This results in corduroy cloud fornations that travel horizontally through the sky.

Image: Atmopsheric gravity waves between Australia and Indonesia in 2008. Source: NASA

Several regions of atmospheric gravity wave clouds could be seen to the northwest of WA on Tuesday, moving in different directions and even intersecting at one stage to from a V-shape.

Atmospheric gravity waves were also spotted off Australia’s northwest coast on Sunday and Monday. This is the same region that saw a huge gravity wave in October 2019, which was accompanied by a large cloud of dust being blown off the drought-weary Australian continent.