Jupiter is the largest planet in our solar system, and its weather is extremely volatile. Beautiful Jupiter images show striped, stormy clouds covering the entire planet. In fact, Jupiter is engulfed in storms. Some are small, but others are so massive that they could cover the entire planet. The most powerful of these storms is the well-known Great Red Spot. This location is a cyclone, similar to hurricanes and cyclones on Earth.
Oceanographers have used images from NASA’s June Spacecraft to create a new study that describes the rich turbulence at Jupiter’s poles as well as the physical forces that drive the large cyclones.
The Juno spacecraft, a NASA-funded satellite that sends images from our solar system’s largest planet to researchers on Earth, is hurtling around Jupiter and its 79 moons. These images provided oceanographers with the raw materials for a new study published today in Nature Physics, which describes the rich turbulence at Jupiter’s poles as well as the physical forces that drive the large cyclones.
These findings gave the researchers clues on the energy of the system. Since Jovian clouds are formed when hotter, less dense air rises, the researchers found that the rapidly rising air within clouds acts as an energy source that feeds larger scales up to the large circumpolar and polar cyclones.
Lia Siegelman
Lia Siegelman, a physical oceanographer and postdoctoral scholar at Scripps Institution of Oceanography at the University of California San Diego, decided to pursue the research after noticing similarities between the cyclones at Jupiter’s pole and ocean vortices she studied as a Ph.D. student. Siegelman and colleagues used an array of these images and geophysical fluid dynamics principles to provide evidence for a long-held hypothesis that moist convection (when hotter, less dense air rises) drives these cyclones.
“When I saw the richness of the turbulence around the Jovian cyclones with all the filaments and smaller eddies, it reminded me of the turbulence you see in the ocean around eddies,” said Siegelman. “These are especially evident on high-resolution satellite images of plankton blooms for example.”
Siegelman says that understanding Jupiter’s energy system, a scale much larger than Earth’s one, could also help us understand the physical mechanisms at play on our own planet by highlighting some energy routes that could also exist on Earth.
“To be able to study a planet that is so far away and find physics that apply there is fascinating,” she said. “It begs the question, do these processes also hold true for our own blue dot?”
Humans have been watching the Great Red Spot for at least 200 years and it has been blowing strong winds almost this whole time. Like all storms, it can change from day to day. Sometimes it looks round, sometimes like an egg. Its colour can also change from brownish-red to pale red. Sometimes it looks almost white. But recently, scientists have noticed the enormous cyclone shrinking. About 100 years ago, the Great Red Spot was almost three times larger than it is today.
Juno is the first spacecraft to photograph Jupiter’s poles; previous satellites orbited the planet’s equatorial region, providing views of the planet’s famous Red Spot. Juno has two camera systems: one for visible light images and another for heat signatures using the Jovian Infrared Auroral Mapper (JIRAM), an instrument supported by the Italian Space Agency.
Siegelman and colleagues examined a collection of infrared images of Jupiter’s north polar region, particularly the polar vortex cluster. The researchers were able to calculate wind speed and direction from the images by tracking the movement of the clouds between images. The team then used infrared images to calculate cloud thickness. Hot regions correspond to thin clouds, through which one can see further into Jupiter’s atmosphere. The cold regions represent the thick cloud cover that covers Jupiter’s atmosphere.
These findings gave the researchers clues on the energy of the system. Since Jovian clouds are formed when hotter, less dense air rises, the researchers found that the rapidly rising air within clouds acts as an energy source that feeds larger scales up to the large circumpolar and polar cyclones.
Juno arrived in the Jovian system in 2016, giving scientists their first look at these massive polar cyclones, which have a radius of about 1,000 kilometers (620 miles). Jupiter’s north pole has eight of these cyclones, and its south pole has five. Since that first sighting five years ago, these storms have been present. Researchers aren’t sure where they came from or how long they’ve been circulating, but they do know that moist convection is what keeps them going. After observing lightning in Jupiter storms, researchers hypothesized this energy transfer.
Juno will remain in orbit around Jupiter until 2025, providing scientists and the general public with new images of the planet and its extensive lunar system.
