Precipitation pattern of the mid-Holocene simulated by a high-resolution regional climate model

Early proxy-based studies suggested that there potentially occurred a “southern drought/northern flood” (SDNF) over East China in the mid-Holocene (from roughly 7000 to 5000 years before present). In this study, we used both global and regional atmospheric circulation models to demonstrate that the SDNF—namely, the precipitation increases over North China and decreases over the the lower reaches of the Yangtze River Valley—could have taken place in the mid-Holocene. We found that the SDNF in the mid-Holocene was likely caused by the lower SST in the Pacific. The lowered SST and the higher air temperature over mainland China increased the land-sea thermal contrast and, as a result, strengthened the East Asian summer monsoon and enhanced the precipitation over North China.