NASA OBPG OB.DAAC/GSFC/Aqua/MODISImage/Gerald Eichstädt)
Earth & Jupiter don’t have much in common.
One is relatively small, rocky & habitable. The other is absolutely huge, completely lacking in solidity, and rages with colossal storms. Yet if you look at a few satellite images of marine phytoplankton blooms here on Earth alongside images of atmospheric turbulence at Jupiter’s poles, it can be difficult to tell them apart.
It’s a striking similarity, and it ultimately led us to an answer as to the cause of Jupiter’s spectacular turbulence: moist-convection. This is when the warmer, less dense air rises and, even at small scale, is enough to cause massive cyclones on the biggest planet in our solar system.
And, fascinatingly, it took ocean scientist to make connection.
“When I saw the richness of turbulence around Jovian cyclones with all the little filaments & small eddies, it reminded me of the turbulence you see in the ocean around the eddies,” said oceanographer Lia Siegelman of the Scripps Institution of Oceanography.
“These are particularly visible on high-resolution satellite images of plankton blooms, for example.
Moist convection was proposed as mechanism behind Jupiter turbulence some time ago, but we did not have access to sufficiently detailed data needed to confirm it. Then Juno arrived on scene. Its orbit around gas giant took it around the poles, allowing us first detailed views of these turbulent regions.
There, scientists saw particular clusters of cyclones 5,000 km wide, with smaller-scale vortices & filaments, ranging from 100 to 1,600 km.
(NASA OBPG OB.DAAC/GSFC/Aqua/MODISImage/JPL/SwRI/MSSS/Gerald Eichstädt)
Juno is equipped with 2 cameras – optical & infrared – with resolutions down-to-scales of 10 km. Siegelman & her colleagues analyzed Juno’s images of the gas giant’s north pole, using optical image sequences to track cloud movements, which in turn provided estimates of wind speed & direction. .
The infrared images allowed them to see temperatures of these images; hotter regions represent thinner clouds & cooler regions represent thicker clouds.
This level of detail allowed the team to understand how turbulence occurs. They found that rapidly increasing convective up-wellings of hot, less dense air from origins less than 100 km across transfers energy upward-into giant cyclones, fueling & sustaining them.
This type of energy transfer has not been observed on any other planet. Interestingly, this looks like idealized studies of rapidly rotating Rayleigh Bénard convection; it is convection where a lower horizontal layer of fluid is heated & rises into cooler layer above. This similarity supports model of moist convection in Jupiter’s polar cyclones.
This discovery began with Earth & a strange similarity between our home planet & Jupiter. It also boomerangs back-to-Earth it might be able to provide insight into our atmospheric processes, the researchers said. Wind observations made here on Earth show a same kinetic energy spectrum to Jovian observations, suggesting that a very similar energy transfer could occur on both planets.
“Being able to study such a distant planet & discover the physics that apply to it is fascinating,” said Siegelman. “The question arises, do these processes also hold true for our blue-dot?
Future investigations will be necessary to confirm this, but this could ultimately contribute to a better understanding of our planet earth.
