Seesaw between the westerlies and Asian monsoon regulates vegetation and climate during the last deglaciation in southern Northeast China

Abstract

The history and drivers of hydroclimate changes during the last deglaciation in Northeast China remain contentious. We present a high-resolution record of vegetation and climate changes from Lake Buridun in southern Northeast China (SNEC), spanning the last ∼16 kyr. Multi-proxy reconstruction reveals a slight increase in precipitation prior to the end of Heinrich Stadial 1 (HS1) and forest development during the middle Bølling warming, indicating that hydrothermal conditions regulated regional vegetation. Significant fluctuations in all millennial-scale climatic events underscore the high sensitivity of SNEC to climate change. Our record aligns with high-resolution data from both SNEC and North China, showing a persistent wetting trend during the Bølling-Allerød period. This trend coincides with changes in East Asian summer monsoon intensity and Indo-Pacific warm pool heat content but contrasts with the Greenland temperature records. During the HS1 and Younger Dryas, records show a cold-dry mode in SNEC, contrasting with the cold-wet pattern in central-eastern China caused by the prolonged Meiyu season, which corresponds to the retreat of the monsoon precipitation belt and an enhanced westerly jet. Our data, along with more comprehensive records from broader regions, suggest that hydroclimate in SNEC was dominated by the low-latitude monsoon and the high-latitude westerlies during the warm and cold phases of the last deglaciation, exhibiting a seesaw-like interaction.