Temperature changes at Saturn's equator: 2004-2016
The atmosphere of Saturn displays a distinctive phenomenon at the 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) at Saturn, and with analogues on Earth and Jupiter–appear to be a defining characteristic of the middle layers of a planetary atmos-phere.
To better understand Saturn's QPO, Leigh Fletcher (University of Leicester, UK) and colleagues studied data from the CIRS instrument on the international Cassini spacecraft, which observed Saturn from June 2004 until 15 September 2017 when the mission concluded by plunging into the gas planet's atmosphere.
The scientists detected a huge disturbance spanning 2011 to 2013, where the whole equatorial region cooled dramatically. This happened directly after the eruption of a giant storm that wrapped around Saturn's entire northern hemisphere, suggesting a link between the two events.
Although the influence of Saturnian storms was known to be substantial, the study suggests an even wider influence than expected, and confirms a connection between Saturn's QPO and re-mote, distinct events occurring elsewhere in the planet's atmosphere.
The animation shows the evolution of temperature changes during the period March 2004 to De-cember 2016.