Microphysical characteristic of clouds over Southern Ocean observed during SOCRATES field campaign

Numerical models have trouble representing clouds over the Southern Ocean (SO) according to the Coupled Model Intercomparison Project Phase 5, which may be due to limited knowledge of cloud microphysical properties and understanding of cloud processes. The remote location of the SO means in-situ cloud observations are very limited there. The recent Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study (SOCRATES) provides the most comprehensive observations of cloud, aerosol and precipitation properties to date. During SOCRATES, based out of Hobart Australia, the NSF/NCAR Gulfstream-V aircraft was equipped with a full set of cloud microphysics instrumentation to sample clouds. A Cloud Droplet Probe is used to measure cloud droplet size distributions (PSDs) from 2 to 50 μm, while a two-dimensional stereo probe and two-dimensional cloud probe measure PSDs from 10-1280 μm and 25-1560 μm, respectively. In addition, the Particle Habit Imager and Polar Nephelometer measures the angular scattering phase function and PSDs for particles in the size range of 20-700 μm. Furthermore, bulk probes, such as King probe, Counterflow Virtual Impactor and Closed Path Laser Hygrometer 2, measure bulk mass. Fifteen flights conducted during SOCRATES provide cloud measurements in various environmental conditions. In this study, multiple probes will be combined to generate an integrated product for ice and liquid-phase cloud microphysical properties, such as the number concentration, water content, and cloud PSDs. These cloud microphysical properties are analyzed as a function of environmental conditions. The unique dataset will also be used for future numerical modeling and remote sensing studies.