Surrounding Jupiter and its 79 moons is the Juno spacecraft, a NASA-funded satellite that sends images of the largest planet in our solar system back to researchers on Earth. These photographs have provided oceanographers with raw material for a new study published today in Natural Physics which describes the rich turbulence at Jupiter’s poles and the physical forces that drive large cyclones.
Lead author Lia Siegelman, a physical oceanographer and postdoctoral fellow at the Scripps Institution of Oceanography at the University of California, San Diego, decided to pursue the research after noticing that cyclones at Jupiter’s pole appear to share similarities with ocean eddies that she studied during her time as a doctoral student. Using an array of these images and principles used in geophysical fluid dynamics, Siegelman and his colleagues provided evidence for a long-held hypothesis that moist convection – when warmer, less dense air rises – drives these cyclones.
“When I saw the rich turbulence around the Jovian cyclones with all the filaments and the smaller eddies, it reminded me of the turbulence you see in the ocean around the eddies,” Siegelman said. “These are particularly evident on high-resolution satellite images of plankton blooms for example. »
Siegelman says understanding Jupiter’s energy system, on a much larger scale than Earth’s, could also help us understand the physical mechanisms at play on our own planet by highlighting some energy pathways that might also exist on Earth.
“To be able to study such a distant planet and find the physics that apply to it is fascinating,” she said. “This begs the question, are these processes also valid for our own blue dot? »
Juno is the first spacecraft to capture images of Jupiter’s poles; previous satellites orbited the planet’s equatorial region, providing views of the planet’s famous red spot. Juno is equipped with two camera systems, one for visible-light images and the other that captures heat signatures using the Jovian Infrared Auroral Mapper (JIRAM), an instrument on the Juno spacecraft supported by the Italian Space Agency.
Siegelman and his colleagues analyzed a set of infrared images capturing Jupiter’s north polar region, and in particular the polar vortex cluster. From the images, the researchers were able to calculate wind speed and direction by tracking the movement of clouds between images. Next, the team interpreted the infrared images in terms of cloud thickness. Warm regions correspond to thin clouds, where it is possible to see deeper into Jupiter’s atmosphere. The cold regions represent thick cloud cover, blanketing Jupiter’s atmosphere.
These findings gave researchers clues to the energy of the system. Since Jovian clouds form when warmer, less dense air rises, researchers have found that the rapidly rising air in the clouds acts as an energy source that fuels more large scale large circumpolar and polar cyclones.
Juno first arrived in the Jovian system in 2016, giving scientists their first glimpse of these large polar cyclones, which have a radius of around 1,000 kilometers or 620 miles. There are eight such cyclones that occur at Jupiter’s north pole and five at its south pole. These storms have been around since that first sight five years ago. Researchers don’t know exactly how they appeared or how long they’ve been circulating, but they now know that moist convection is what sustains them. Researchers first hypothesized this energy transfer after observing lightning during thunderstorms on Jupiter.
Juno will continue to orbit Jupiter until 2025, providing researchers and the public with new images of the planet and its vast lunar system.
Seigelman is funded by the Scripps Institution of Oceanography Postdoctoral Program, working in the laboratory of physical oceanographer William Young, whose work is supported by the National Science Foundation.
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Materials provided by University of California–San Diego. Original written by Lauren Fimbres Wood and Chase Martin. Note: Content may be edited for style and length.