Find it Online: https://doi.org/10.3390/rs18132262
Highlights
Cloud and drizzle properties in Southern Ocean (SO) marine boundary layer clouds were examined using aircraft, shipborne, and satellite observations to compare how different observational platforms detect and characterize the similar cloud regimes sampled over the same SO region during the austral summer season.
What are the main findings?
- Consistent cloud–drizzle retrievals across platforms. The reflectivity–retrieval framework provides consistent macrophysical and microphysical properties of liquid-dominant SO MBL clouds and drizzle from airborne (SOCRATES), ship-based (MARCUS), and satellite (CloudSat) observations.
- Retrieved cloud structures are physically realistic, while instrumental limitations explain most differences. The retrieved vertical distributions of cloud and drizzle properties are consistent with the dominant physical growth processes. Differences among the three platforms reflect variations in radar sensitivity, vertical resolution, and sampling strategy.
What are the implications of the main findings?
- Toward unified cloud–drizzle retrievals. A single in situ-derived reflectivity–microphysics framework can be applied across airborne, ship-based, and satellite radars, enabling more coherent multi-platform cloud and drizzle climatologies.
- Stronger confidence in MBL cloud process interpretation. The retrieved cloud–drizzle structures across platforms support robust physical interpretations of SO MBL clouds and provide a benchmark for improving retrievals and climate model evaluation.
Abstract
Marine boundary layer (MBL) clouds strongly influence radiation and precipitation over the Southern Ocean (SO), yet their vertical structures and microphysical properties remain poorly constrained across observational platforms. This study compares macrophysical and microphysical properties of single-layer, liquid-dominant MBL clouds below 3 km using aircraft observations from the SO Clouds, Radiation, Aerosol Transport Experimental Study (SOCRATES), ship-based observations from Measurements of Aerosols, Radiation, and Clouds over the SO (MARCUS), and satellite observations from CloudSat. An empirical reflectivity–microphysics retrieval framework developed from in situ droplet size distributions (DSDs) measured during SOCRATES was applied to MARCUS M-WACR and CloudSat CPR reflectivity observations to retrieve vertical profiles of number concentration (N), effective radius (re), and liquid water content (LWC) for cloud and drizzle particles. Cloud boundary heights and retrieved microphysical properties show broad agreement across the three platforms within the limitations imposed by instrumental sensitivity, sampling differences, and retrieval uncertainties. However, CloudSat CPR observations exhibit larger deviations because of their coarser vertical resolution and lower reflectivity sensitivity, including limited detection of low clouds below ~500 m. The observed vertical structures are consistent with condensational growth, entrainment, and collision–coalescence processes. Overall, the results demonstrate broad consistency in cloud and drizzle properties across the three platforms, while highlighting the impacts of instrumental sensitivity, vertical resolution, and sampling differences on cloud boundary detection and microphysical retrievals.
Cite Paper: Das, A., Dong, X., & Xi, B. (2026). Cross-Platform Comparison of Marine Boundary Layer Cloud and Drizzle Properties over the Southern Ocean Using Airborne, Shipborne, and Satellite Observations. Remote Sensing, 18(13), 2262. https://doi.org/10.3390/rs18132262