Hydroclimatic Evolution of the Southwestern Tibetan Plateau Since the Last Glacial Maximum Inferred from Multi-Proxy Data in Lake Zabuye

Hydroclimatic variations on the Tibetan Plateau since the Last Glacial Maximum (LGM) are still debated. Here, we reconstruct climatic and hydrological variability in the southwestern Tibetan  Plateau since the late LGM using climate proxies based on molecular distributions of n-alkanes, hydrogen and carbon isotopic composition of terrestrial n-alkanes and δ¹⁸O_carbonate at Lake Zabuye. Our findings indicate that the δD-nC₃₁ signal in this lake was primarily influenced by temperature from late the LGM to early deglaciation period, shifting to a predominance of precipitation influence from the Heinrich event 1 (H1) to the Holocene period. In contrast, the carbonate δ¹⁸O was found to be primarily governed by evaporative processes. Through comprehensive analysis of all proxies, we suggest that Lake Zabuye was dominated by the mid-latitude Westerlies with cold and moist conditions from late LGM to early deglaciation. The H1 and Younger Dryas (YD) periods were characterized by low temperature and reduced precipitation due to the influence of the moderately intensified Westerlies. The Indian Ocean Summer Monsoon (IOSM) intensified during the Bølling/Allerød (B/A) period, and its strength was comparable to that of the Westerlies, resulting in plentiful rainfall and high evaporation. The IOSM was dominant during the Holocene, characterized by abundant rainfall and high evaporation.