Hurricanes hover like oceans on Jupiter

Swirling cyclones in the turbulent atmosphere of gaseous Jupiter look beautiful. Oceanographer Leah Segelman was shocked by something other than the beauty of the whirlpools. “It reminded me of images of the turbulent ocean around Antarctica that I was examining at the time,” she says.

This observation led to a study in which Siegelman, of the University of California, and colleagues now provide the first evidence that Jupiter’s giant cyclones are driven by the same type of convection currents that create ocean eddies dozens of times smaller on Earth. In Jupiter’s atmosphere, it’s about gas flows and in the ocean around water, but from a physical perspective, they’re “liquids” that you can describe with the same principles of fluid dynamics, Siegelman explains in an email. its results Noon last week in a Nature Physics.

In the atmosphere of Jupiter, the largest planet in our solar system, thousands of kilometers thick, hurricanes ignite hundreds to thousands of kilometers in size with winds of more than 250 kilometers per hour. At the north pole of Jupiter you will find eight of these giant cyclones and at the south pole five. And they don’t just explode. Cyclones at the poles have been raging since they first appeared in 2016 Captured for Juno space probe. How they form is still unknown, but by mapping the motions of ammonia-rich Jupiter’s clouds, Siegelman and colleagues have now shown how they are triggered.

The researchers analyzed a series of infrared images from Juno that captured the eight hurricanes at Jupiter’s north pole. Infrared images, with a resolution of about ten kilometers per pixel, show the temperature of the cloud cover. In hot regions, there are thin drooping clouds that allow you to see deeper into the hot atmosphere of Jupiter. Dense and high clouds cover that hot air, making it seem cooler out there.

up and sideways

By comparing infrared images taken by Juno in quick succession, the researchers were able to track both the upward and lateral movement of the clouds. For example, they saw how fast and in which direction neighboring tornadoes and vortices were spinning and growing.

“We’ve seen that hurricanes are driven by moist convection currents,” Siegelman says. Warm air of low density rises from the deep atmosphere. Cooler air, with a higher density, falls to the bottom. This creates turbulent vortices in the ammonia clouds. This supplies energy to hurricanes. The suspicion that the giant hurricanes of Jupiter are being pushed in this way is not new. The idea has been around for some time and is backed by computer simulations. But oceanographers’ research is providing clues for the first time.

Siegelman continues her investigation of the swirling gas giant and is looking forward to new photos of Juno. “Jupiter and its rich turbulence are wonderful.”