Despite their considerable differences, the equatorial middle atmospheres of Earth, Jupiter, and Saturn all exhibit a similar phenomenon: vertical, cyclic 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 Quasi-Biennial Oscillation (QBO) — appear to be a defining characteristic of the middle layers of a planetary atmosphere.
