Intermodel relation between present-day warm pool intensity and future precipitation changes

Tropical convection plays a key role in regional and global climate variability, and future changes in tropical precipitation under anthropogenic global warming are critical for projecting future changes in regional climate. In this study, by analyzing Coupled Model Intercomparison Project (CMIP) phase 6 models, we show that changes in projected tropical precipitation in CMIP6 models vary among models, but they are largely associated with the model's warm pool intensity in the present-day (PD) climate. Models with stronger warm pools in the PD simulation tend to simulate an increase in precipitation in the central Pacific (CP) and a decrease in precipitation in the Maritime Continent (MC) under greenhouse warming. Significant differences in precipitation between the CP and MC regions induce low-level westerly anomalies over the west-central Pacific, favoring sea surface temperature warming in the CP region. This suggests that the associated air-sea interactions result in a particular tropical pattern in response to anthropogenic forcing.

Automated summary

Tropical convection plays a crucial role in climate variability, and the study found that changes in projected tropical precipitation vary among CMIP6 models but are closely related to the model's warm pool intensity. Models with stronger warm pools tend to simulate increased precipitation in the central Pacific and decreased precipitation in the Maritime Continent under greenhouse warming. The precipitation differences between these regions induce westerly wind anomalies, leading to sea surface temperature warming in the central Pacific.