Simulation of the Changing Insolation‐Precipitation Relationship Over East Asia During the Holocene

Abstract Although summer insolation decreased continuously throughout the Holocene, geological evidence suggests that precipitation over North and South China exhibited out‐of‐phase variations before the middle Holocene, followed by in‐phase variations afterward. This proxy‐based altered relationship between insolation and East Asian precipitation is also obvious in an accelerated transient Holocene experiment. The simulation indicates that the East Asian summer monsoon strength directly responds to the insolation change, failing to explain the varying insolation‐precipitation relationship. However, the western Pacific subtropical high (WPSH) can modulate the moisture transport over East Asia, playing a crucial role in shaping the precipitation response to insolation. During the Holocene, the position and intensity of WPSH are determined not only by changes in insolation but also by changes in its meridional gradient, which could explain the shift in the insolation‐precipitation relationship around the middle Holocene. This conclusion provides a possible mechanism for the asynchronous Holocene optimum of East Asian precipitation.