In situ observations of supercooled liquid clouds over the Southern Ocean during the HIAPER Pole-to-Pole Observation campaigns

However, in situ observations of these clouds are rare, and the dominant precipitation processes are unknown. Uncertainties in their life cycles and radiative properties make them interesting from a weather and climate perspective.

Data from the standard cloud physics payload during the High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observations global transects provide a unique snapshot the nature of low-level clouds in the Southern Ocean. High quantities of supercooled liquid water (up to 0.47gm⁻³) were observed in clouds as cold as -22°C during two flights in different seasons and different meteorological conditions, supporting climatologies inferred from satellite observations.