The Asian summer monsoon, as a significant way of transporting water vapor and heat to the mainland, has an obvious effect on environmental change, regional ecological security, and economic development. It is of great practical significance to study the changes in the Asian summer monsoon and its impact on regional hydrology and climate during the geology-historical period, especially the typical warming period. Located on the edge of the modern Asian summer monsoon, the northeast of Tibet Plateau has a fragile environment that is sensitive to the variation of the summer monsoon. At present, due to using diverse materials reconstructing the paleoenvironment, predecessors have a different understanding of the variation pattern and driving mechanism of Asian summer monsoon since the Last Glacial Maximum (LGM).

Academician Chen Fahu and Dr. Wu Duo, from the College of Earth and Environmental Sciences, have written articles to sort out the climate environment change of this region in Holocene by the record of Qinghai Lake and proposed that under the control of East Asia summer monsoon, this region had more precipitation in the early and middle Holocene, especially in middle Holocene, and the precipitation decreased in late Holocene (Chen F H, Wu D et al., 2016, Quaternary Science reviews). Meanwhile, the result from this academic team showed that the temperature of China during early to middle Holocene is higher in summer (Wu D et al., 2018, Quaternary Science reviews).

The academic team further used the sedimentary core of the Dalianahai Lake in the Republican Basin in the northeastern Tibetan Plateau to correct carbon pool effect through multi-level Stepwise Polynomial Regression based on the AMS14C chronological data of 11 terrestrial plant residues and 14 all-organic samples, and eventually built a reliable chronological framework over the past 23,000 years. Then the hydrological and climatic changes of the Republican Basin since LGM (Figure.1) was reconstructed by analyzing sedimentary indicator (particle size) and geochemical indicators (carbon isotopes of carbonate, TOC, GDGTs, etc.) of the sediment samples. The results of this study are of warning signs to the variation and utilization of water resources in arid and semi-arid areas on the current and future background of global warming.

With the title of "Temperature-induced dry climate in basins in the northeastern Tibetan Plateau during the early to middle Holocene", the results of their study were published by “Quaternary Science reviews” (Geology Q1, top). Young researcher Dr. Wu Duo is the first author and first corresponding author and Professor Zhou Aifeng is the second corresponding author. The College of Earth and Environmental Science is the first labeling institution. The research was jointly funded by the National Natural Science Foundation Youth Science Foundation Project (41807442) and Major projects (41991251), the Chinese Postdoctoral Science Foundation Special Funding Project (2019T120962), and the Second Tibetan Plateau Scientific Expedition and Research (2019QZKK0601).

Article link: https://www.sciencedirect.com/science/article/pii/S0277379120302730

Fig.1 Comparison between climate change records of the northeastern Tibetan Plateau and global bulb-temperature and precipitation records over the past 15000 years