Galileo Probe Doppler residuals as the wave‐dynamical signature of weakly stable, downward‐increasing stratification in Jupiter's deep wind layer

Doppler radio tracking of the Galileo probe‐to‐orbiter relay, previously analyzed for its in situ measure of Jupiter's zonal wind at the equatorial entry site, also shows a record of significant residual fluctuations apparently indicative of varying vertical motions. Regular oscillations over pressure depth in the residual Doppler measurements of roughly 1–8 Hz (increasing upward), as filtered over a 134 sec window, are most plausibly interpreted as gravity waves, and imply a weak, but downward increasing static stability within the 5‐20 bar region of Jupiter's atmosphere. A matched extensio to deeper levels of an independent inertial stability constraint from the measured vertical wind shear at 1‐ 4 bars is roughly consistent with a static stability of ∼0.5 K/km near the 20 bar level, as independently detected by the probe Atmospheric Structure Instrument.