Saturn's equatorial oscillation: Evidence of descending thermal structure from Cassini radio occultations

A series of near‐equatorial radio occultations of Cassini by Saturn occurred in 2005 and again in 2009–2010. Comparison of the temperature‐pressure profiles obtained from the two sets of occultations shows evidence of a descending pattern in the stratosphere that is similar to those associated with equatorial oscillations in Earth's middle atmosphere. This is the first time that this descent has been observed in another planetary atmosphere. If absorption of upwardly propagating waves drives the descent, the implied absorbed flux is 0.05 m2 s−2, at least as large if not greater than on Earth. Key Points An equatorial oscillation is observed in Saturn's atmosphere Descending pattern in the temperature‐pressure profile is observed This is analogous to a similar well observed oscillation on the Earth