Saturn's Gargantuan Northern Storms Disrupt Atmospheric Patterns At The Equator: Cassini Shows

A new study used data from NASA’s Cassini mission and found the gargantuan storms in the northern part of Saturn can disrupt the atmospheric patterns over the ringed planet's equatorial region. Researchers from the University of Leicester observed this effect and found several parallels to a similar phenomenon on Earth, which suggests more similarities between the two very distinct planets of the solar system.

Apart from Earth and Saturn, similar effects have been observed on Jupiter also. These patterns are called different names in different planets. On Saturn, it’s known as Quasi-Periodic Oscillation (QPO) and Quasi-Quadrennial Oscillation (QQO) on Jupiter. Now, researchers said Saturn’s QPO is very similar to Earth's so-called Quasi-Biennial Oscillation (QBO). These effects are said to have a profound reactions on the middle layers of a planet's atmosphere.

The three planets are very different in composition, size, position in the solar system, atmospheric composition and topography. But, similar phenomena have been observed now in their equatorial regions in the vertical, cyclical, downwards-moving patterns of alternating temperatures and wind systems, which are cyclic processes that modify the atmosphere over the equatorial region.

Earth's QBO was studied and found to cycle every 28 months on average. However, it is constantly disrupted by atmospheric processes far from the region above the equator, like Saturn.

"These oscillations can be thought of as a planet's heartbeat," says Leigh Fletcher of the University of Leicester, UK, lead author of the study (published in Nature Astronomy ) and co-investigator of Cassini's Composite Infrared Spectrometer (CIRS) in a press release on the ESA website. "Cassini spotted them on Saturn about a decade ago, and Earth-based observations have seen them on Jupiter, too. Although the atmospheres of the distant gas giants may appear startlingly different to our own, when we look closely we start to discover these familiar natural patterns," she added.

"We looked at data of Saturn's 'heartbeat', which repeats roughly every 15 Earth years, and found a huge disturbance — a palpitation, to continue the metaphor — spanning 2011 to 2013, where the whole equatorial region cooled dramatically," said co-author Sandrine Guerlet from Laboratoire de Météorologie Dynamique (LMD), France.

The timing was calculated and it was found the phenomenon happened directly after the eruption of a giant storm in the entire northern hemisphere of the planet. This storm, known as the Great Northern Storm occurs roughly once every Saturnian year, which is equivalent to 30 Earth years.

Cassini observed the storm in great detail from the orbit and captured data for the study.

"We became especially excited when we compared this palpitation on Saturn to one observed in Earth's QBO in 2016: it was disturbed in a similar way by waves carrying momentum from Earth's northern hemisphere to the equator," said Fletcher.

Meteorological patterns on Earth are delicately linked together and there is a cause and effect involved in atmospheric phenomenon.

"It's remarkable to see this process occurring on another planet within our Solar System — especially one that's so vastly different to our own," Nicolas Altobelli, ESA Project Scientist for the Cassini-Huygens mission, said.

Cassini-Huygens ended its mission earlier this year in September when it dove into Saturn’s atmosphere, but there is a lot of data left to study. The team hopes understanding other planets could help them figure out processes on Earth.

The study was published in journal Nature Astronomy on Oct. 23.