Ocean physics explain cyclones on Jupiter
Images from NASA satellite of polar cyclones on Jupiter allow scientists
to study the forces that drive them

Date:
January 10, 2022
Source:
University of California - San Diego
Summary:
Images from NASA's June Spacecraft have given oceanographers the
raw materials for a new study that describes the rich turbulence
at Jupiter's poles and the physical forces that drive the large
cyclones.



FULL STORY ========================================================================== Hurtling around Jupiter and its 79 moons is the Juno spacecraft,
a NASA-funded satellite that sends images from the largest planet in
our solar system back to researchers on Earth. These photographs have
given oceanographers the raw materials for a new study published today
in Nature Physicsthat describes the rich turbulence at Jupiter's poles
and the physical forces that drive the large cyclones.


==========================================================================
Lead author 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 that
the cyclones at Jupiter's pole seem to share similarities with ocean
vortices she studied during her time as a PhD student. Using an array of
these images and principles used in geophysical fluid dynamics, Siegelman
and colleagues provided evidence for a longtime 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?" Juno is the first
spacecraft to capture images of Jupiter's poles; previous satellites
orbited the equatorial region of the planet, providing views of the
planet's famed Red Spot. Juno is equipped with two camera systems,
one for visible light images and another 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 colleagues analyzed an array of infrared images capturing Jupiter's north polar region, and in particular the polar vortex
cluster. From the images, the researchers could calculate wind speed and direction by tracking the movement of the clouds between images. Next,
the team interpreted infrared images in terms of cloud thickness. Hot
regions correspond to thin clouds, where it is possible to see deeper
into Jupiter's atmosphere. Cold regions represent thick cloud cover,
blanketing 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 first arrived at the Jovian system in 2016, providing scientists with
the first look at these large polar cyclones, which have a radius of about 1,000 kilometers or 620 miles. There are eight of these cyclones occurring
at Jupiter's north pole, and five at its south pole. These storms have
been present since that first view five years ago. Researchers are unsure
how they originated or for how long they have been circulating, but they
now know that moist convection is what sustains them. Researchers first hypothesized this energy transfer after observing lightning in storms
on Jupiter.

Juno will continue orbiting Jupiter until 2025, providing researchers
and the public alike with novel images of the planet and its extensive
lunar system.

Seigelman is funded through the Scripps Institution of Oceanography Postdoctoral Program, working in the lab of physical oceanographer
William Young, whose work is supported by the National Science Foundation.

========================================================================== Story Source: 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.


========================================================================== Journal Reference:
1. Siegelman, L., Klein, P., Ingersoll, A.P. et al. Moist convection
drives
an upscale energy transfer at Jovian high latitudes. Nat. Phys.,
2022 DOI: 10.1038/s41567-021-01458-y ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/01/220110114140.htm
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