Known as noctilucent clouds or polar mesospheric clouds (PMCs), a better understanding of these unusual phenomena will help scientists understand turbulence in the atmosphere – and could even play a role in weather forecasting.
The clouds are visible shortly after the sun sets in polar regions during the summer, as ice forms around meteor remnants in the upper atmosphere.
“Our cameras were likely able to capture some really interesting events and we hope will provide new insights into these complex dynamics,” said Dr Dave Fritts, who led the PMC Turbo mission.
The balloon used in the mission floated through the stratosphere for five days, and cameras on board captured six million high-resolution images.
So-called atmospheric gravity waves, caused by masses of air being pushed up when they meet obstacles like mountain ranges, also play a role in the clouds’ appearance.
“This is the first time we’ve been able to visualise the flow of energy from larger gravity waves to smaller flow instabilities and turbulence in the upper atmosphere,” said Dr Fritts.
“At these altitudes you can literally see the gravity waves breaking – like ocean waves on the beach – and cascading to turbulence.”
More about: NASA