Sea–air coupling leads to a decrease in precipitation in East Asia under present day conditions that is partially alleviated in future simulations

Abstract

The offshore region of East Asia has a crucial role in recycling precipitation, especially in the current context of a warming climate. This is because the atmospheric feedback from the sea offshore East Asia directly impacts and modifies precipitation patterns by influencing the seasonal cycles of the surface energy and water budgets. We used a regional climate model incorporating sea–air coupling to investigate and better understand these climate feedback mechanisms in East Asia. We identified a reduction in precipitation caused by sea-air coupling over East Asia during the time period 1991 − 2014 under present day conditions. Specifically, we observed an average decrease in precipitation of about 0.1 ± 0.40 mm day−1 during June–July–August. This decrease in precipitation can be attributed to a combination of factors, including the effects of upward solar radiation, the asymmetry of the thermal contrast between the land and the sea, decreased evaporation in the southeastern ocean and the weakened transport of water vapor from the sea to the land. Our research suggests that the decrease triggered by sea–air coupling will be partially alleviated under future conditions, although not completely reversed, in terms of its impact on precipitation in eastern China. Although some relief is anticipated, the overall influence of sea–air coupling on patterns of precipitation in East Asia will persist, especially south of the Yellow River in eastern China.