Fluid & BioDynamics Seminar: Turbulence and Supercool Clouds in Antarctica: the field campaign

In this talk, I will present results from the T-SCAN (Turbulence and Supercooled Clouds in Antarctica) campaign, conducted in January 2025 from Marambio Base near the Antarctic Peninsula. Using 32 daily radiosoundings corrected for humidity biases and analyzed with the moist potential temperature (θ*), we examined how phase changes and supersaturation influence tropospheric stability and turbulence. The analysis combines a humidity correction scheme with Thorpe-scale diagnostics and a turbulent-fraction index based on dry and moist stability criteria. Results show extended layers supersaturated with respect to ice above ~2 km, often associated with mixed-phase cloud conditions. Thorpe lengths derived from θ* are systematically larger than those from dry potential temperature, indicating enhanced overturning when latent heating is included. The turbulent fraction under moist conditions is on average ~47 % higher, with underestimations exceeding 50 % in nearly half of the flights. These findings reveal how moist processes and ice supersaturation substantially modify turbulence and vertical mixing over coastal Antarctica.