UTLS dynamics studied with ROMEX radio occultation measurements

Dense radio occultation measurements from the ROMEX experiment (>35,000 occultations per day over September-November 2022) are used to analyze large- and small-scale thermal variability in the global UTLS. We quantify large-scale equatorial waves near the tropical tropopause and document enhanced small-scale variability (gravity waves) linked with persistent tropical convection. The convectively forced gravity waves are modulated by the large-scale waves in the lower stratosphere. We also highlight enhanced small-scale waves that overlay the midlatitude jets in both hemispheres, which are likely signatures of gravity waves linked to jet dynamics. The dense ROMEX data provide novel observations to study coupling of large- and small-scale waves in the UTLS.