Earth-system-model evaluation of cloud and precipitation occurrence for supercooled and warm clouds over the Southern Ocean's Macquarie Island

A year-long study at Macquarie Island, part of the UNESCO-listed Southern Ocean, reveals that liquid-phase clouds precipitate approximately 70% of the time, with deeper and colder clouds showing higher precipitation frequency and intensity. Supercooled cloud layers also precipitate more readily than warmer ones, regardless of thickness. The research utilized ground-based profiling instruments during the Macquarie Island Cloud and Radiation Experiment (MICRE) to evaluate a 9-year Earth-system-model simulation using the GISS-ModelE3. The model, processed through the Earth Model Column Collaboratory (EMC 2), showed deficiencies in cloud occurrence and precipitation frequency but accurately reproduced observed tendencies for deeper clouds to precipitate more frequently. This study demonstrates a valuable framework for evaluating cloud radiative feedbacks in Earth-system models.

Stanford, M. W., Fridlind, A. M., Silber, I., Ackerman, A. S., Cesana, G., Mülmenstädt, J., Protat, A., Alexander, S., & McDonald, A. (2023). Earth-system-model evaluation of cloud and precipitation occurrence for supercooled and warm clouds over the Southern Ocean’s Macquarie Island. Atmospheric Chemistry and Physics, 23(16), 9037–9069. https://doi.org/10.5194/acp-23-9037-2023