High-Resolution Insights from the Max Planck CloudKite During EUREC4A

We present the first results from the Max Planck CloudKite (MPCK) measurements conducted during the EUREC4A campaign in 2020, targeting shallow cumulus clouds in the trade wind regions near Barbados. The MPCK is a 250 m³ tethered balloon stabilized with a kite, capable of carrying up to 100 kg of scientific payload in no-wind conditions or heavier payloads in windy conditions, reaching altitudes of up to 2 km above ground level. During EUREC4A, we performed airborne measurements of cloud microphysics and turbulence using the MPCK⁺ instrument box, which combines fast inline holography with Particle Image Velocimetry (PIV) to resolve micrometer-scale features. The low true airspeed of the tethered balloon, combined with the high sampling frequencies of our imaging setups—15 Hz for PIV and 75 Hz for holography—provided unprecedented detail into the dynamics of shallow cumulus clouds. To date, we have analyzed over 300,000 holograms and 100,000 PIV images acquired during the campaign. Our analysis spans the structure of these clouds from their edges to their cores. We present results on droplet clustering, void formations, the influence of turbulence, and the mechanisms of entrainment and mixing. As clouds remain a major source of uncertainty in climate and weather models, we believe these findings represent a significant step forward in understanding cloud dynamics and their broader implications for atmospheric processes.