The properties of Southern Ocean (SO) liquid phase non precipitating clouds (hereafter clouds) are examined using shipborne data collected during the Measurements of Aerosols, Radiation and Clouds over the Southern Ocean (MARCUS) and the Clouds Aerosols Precipitation Radiation and atmospheric Composition Over the SoutheRN ocean (CAPRICORN) I and II campaigns that took place in the Southern Ocean south of Australia during 2016 and late 2017 into early 2018. The cloud properties are derived using W-band radar, lidar, and microwave radiances using an optimal estimation algorithm. The SO clouds tended to have larger liquid water paths (LWP, 115 ±117 g m-2), smaller effective radii (, 8.7 ±3um), and higher number concentrations (, 90 ±107 cm), than typical values of eastern ocean basin stratocumulus. The clouds demonstrated a tendency for the LWP to increase with presumably due to precipitation suppression up to of approximately 100 cm when mean LWP decreased with increasing . Due to higher optical depth, cloud albedos were less susceptible to changes in compared to subtropical stratocumulus. The high latitude clouds observed along and near the Antarctic coast presented a distinctly bimodal character. One mode had the properties of marine clouds further north. The other mode occurred in an aerosol environment characterized by high cloud condensation nuclei concentrations and elevated sulfate aerosol without any obvious continental aerosol markers that had much higher , smaller and overall higher LWP suggesting distinct sensitivity of the clouds to seasonal biogenic aerosol production in the high latitude regions.