Increasing Risk of a "Hot Eastern‐Pluvial Western" Asia.

Observations have revealed that the deadly "hot eastern‐pluvial western" climate pattern in Asia in summer 2022 is by no means an exception. In recent decade this pattern is becoming much more frequent owing to the notable westward extension and enhancement of the western Pacific subtropical high (WPSH). The anomalously enhanced WPSH fills the gap in geopotential heights between the Arabian Sea‐Iranian Plateau and the western Pacific, produces a heat dome over eastern Asia and intensifies the moisture convergence over western Asia by changing the water vapor transportation path. Projections of 19 CMIP6 models show that both the temperature in eastern Asia and precipitation in western Asia will remarkably increase under Shared Socioeconomic Pathway (SSP) 2‐4.5, SSP 3‐7.0, and SSP 5‐8.5 scenarios, with temperature anomalies 0.8°C, 1.5°C, and 2.4°C higher and the percentages of precipitation anomaly 6.3%, 9.4%, and 12.5% larger than the reference period in the near, middle, and long terms under the moderate emission scenario (SSP2‐4.5). Therefore, the "hot eastern‐pluvial western" Asia is becoming a new normal and exacerbating the risk of compound disasters. Plain Language Summary: In summer 2022, eastern Asia experienced the most extensive and long‐lasting heatwave since 1951, while exceptional floods hit western Asia during the same period. It is found that this "hot eastern‐pluvial western" pattern has occurred more and more frequently since 1981. This could be attributed to the linear trend of the westward extension and enhancement of the western Pacific subtropical high. In this paper, we assess the expected changes by using the latest generation of global climate model projections. The "hot eastern‐pluvial western" climate pattern and the associated atmospheric circulations are projected to increase from 2020s to the end of the 21st century under different greenhouse gas emission scenarios, suggesting more fatal heatwaves in eastern Asia and floods in western Asia in the future. Key Points: The catastrophic climate pattern of "hot eastern‐pluvial western" Asia occurred frequently in recent decades especially in summer 2022The increasing trend of this pattern could be attributed to the westward extension and enhancement of the western Pacific subtropical highProjections of CMIP6 models show that the "hot eastern‐pluvial western" will occur normally in future [ABSTRACT FROM AUTHOR]