Calculating the acoustic and internal gravity wave dispersion relations in Venus's supercritical lower atmosphere.

This article focuses on investigating the acoustic and internal gravity wave properties in Venus’s supercritical lower atmosphere by integrating the Peng–Robinson real-gas equation of state (PR-EoS) with fluid dynamics equations. It demonstrates that Venus’s extreme surface pressure and temperature create supercritical fluid (SCF) conditions, under which ideal-gas assumptions fail, affecting key parameters such as sound speed, density gradients, buoyancy frequency, and atmospheric stability. The study finds that both the acoustic cutoff frequency and buoyancy frequency in Venus’s deep atmosphere are lower than on Earth, and that traditional potential temperature formulations—whether ideal-gas or real-gas based—do not adequately characterize Venus’s atmospheric stability. These findings provide a foundation for interpreting atmospheric acoustic signals related to Venus’s interior geodynamics and support future remote sensing efforts using balloon-based acoustic sensors.