News | December 13, 2017
Giant Storms Cause Palpitations in Saturn's Atmospheric Heartbeat
This series of images track the development of a giant storm whirling over Saturn's mid-northern latitudes in December 2010, as seen at visible wavelengths during much of 2011. Full image and caption › Image Credit: NASA/JPL-Caltech/Space Science Institute
Immense northern storms on Saturn can disturb atmospheric patterns at the planet's equator, finds the international Cassini mission. This effect is also seen in Earth's atmosphere, suggesting the two planets are more alike than previously thought.
Despite their considerable differences, the atmospheres of Earth, Jupiter, and Saturn all display a remarkably similar phenomenon in their equatorial regions: vertical, cyclical, downwards-moving patterns of alternating temperatures and wind systems that repeat over a period of multiple years.
These patterns–known as the Quasi-Periodic Oscillation (QPO) on Saturn and the Quasi-Quadrennial Oscillation (QQO) on Jupiter, due to their similarities to Earth's so-called Quasi-Biennial Oscillation (QBO)–appear to be a defining characteristic of the middle layers of a planetary atmosphere.
Earth's QBO is regular and predictable, repeating every 28 months on average. However, it can be disrupted by events occurring at great distances from the equator of our planet–and a new study reveals that the same is true of Saturn's QPO.
"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). "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."