Against the backdrop of climate change, the interaction between the ocean and the atmosphere plays a crucial role in the water cycle in East Asia. The coupling of ocean in regional Earth system models has been widely acknowledged in climate research in East Asia. Several studies indicate that models with ocean coupling can more accurately capture climate characteristics and interannual precipitation changes compared to non-coupled models. However, many regional climate models currently focus more on interactions between land and the atmosphere, neglecting the essential connection between the ocean and the atmosphere, limiting the in-depth understanding of atmospheric-ocean dynamics.
To address this gap, Dr. Peng Jing, a researcher at the Key Laboratory of East Asian Climate and Environment at the Institute of Atmospheric Physics, Chinese Academy of Sciences, and collaborators conducted a study. They analyzed the impact and related mechanisms of the ocean-atmosphere coupling mechanism on precipitation in East Asia based on a regional Earth system model that incorporates ocean-atmosphere coupling. The study revealed how ocean-atmosphere coupling influences precipitation in East Asia through dynamic and thermal processes.
The research indicates that, from 1991 to 2014, the coupling of the ocean and the atmosphere led to a reduction in summer (June-July-August) precipitation in East Asia. This reduction can be attributed to various factors, including the decrease in thermal asymmetry between land and ocean, reduced ocean evaporation in the northwest Pacific, and weakened water vapor transport from the ocean to the land. Under future conditions, especially in eastern China, the reduction in precipitation caused by the coupling of the ocean and the atmosphere will be somewhat alleviated. However, the overall impact of ocean-atmosphere coupling on the precipitation pattern in East Asia will persist, particularly in the region south of the Yellow River in eastern China.
This study highlights the importance of the interaction between the ocean and the atmosphere in the water cycle and precipitation in East Asia. The research findings were recently published in the npj Climate and Atmospheric Science journal. 
This research received joint funding from the National Key Research and Development Program of China (Project No. 2018YFA0606004). 
Peng, J., Li, K., Dan, L. et al. Sea–air coupling leads to a decrease in precipitation in East Asia under present day conditions that is partially alleviated in future simulations. npj Clim Atmos Sci 6, 174 (2023).
Article Link:  https://doi.org/10.1038/s41612-023-00498-w  

Figure1. Diagram illustrating changes in East Asian precipitation with a regional Earth system model lacking ocean processes