Title: The Revival of Radio Occultations: Investigating the Atmospheres of Jupiter and Saturn Speaker: Dr. Maria Smirnova (Weizmann Institute of Science) Abstract: Radio occultation (RO) is a uniquely powerful technique for probing giant planet atmospheres. As a spacecraft radio signal passes behind the planetary limb, it is refracted by the atmosphere, and the measured changes in the signal can be inverted to retrieve high-vertical-resolution profiles of refractivity, density, pressure, and temperature from the upper troposphere into the stratosphere. At rapidly rotating and strongly oblate planets, these measurements require dedicated ray-tracing inversions that account for planetary shape, gravity, winds, and the full radio-path geometry. At Jupiter, NASA’s Juno mission has produced the first new atmospheric radio occultations since Voyager. Since 2023, we have retrieved more than 50 temperature-pressure profiles spanning low, mid, and polar latitudes, with measurements reaching depths of about 0.6 bar. This growing dataset is now allowing us to compare Jupiter’s thermal structure across various dynamical regimes. Recent observations probe the cold northern polar stratospheric vortex and regions close to the polar cyclones, while lower-latitude profiles reveal variations in atmospheric stability and vertical structure. Together, these measurements provide new constraints on coupling between the stratosphere and upper troposphere, as well as on vertical mixing, waves, and large-scale dynamics. Comparison with TEXES and Cassini’s CIRS observations places the Juno profiles within a broader picture of Jupiter’s spatial and temporal thermal variability. At Saturn, we are revisiting the extensive but still largely underexplored Cassini radio occultation archive, comprising more than 75 atmospheric RO measurements collected over the mission’s 13-year tour. These observations span a wide range of latitudes and the transition from northern winter toward northern summer, p

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