Warming-induced northwestward migration of the East Asian monsoon rain belt from the Last Glacial Maximum to the mid-Holocene
作者单位：Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences
会议名称：《中国科学院地质与地球物理研究所2015年度（第15届）...》
会议日期：2016年
学科分类：070903[理学-古生物学与地层学(含：古人类学)] 0709[理学-地质学] 07[理学]
基 金：supported by Chinese Academy of Sciences Grants XDA05120204 and XDB03020503 National Natural Science Foundation of China Grants 41172157 and 41472318
关 键 词：C4 plants loess East Asian summer monsoon Last Glacial Maximum Holocene
摘 要：Glacial–interglacial changes in the distribution of C/C vegetation on the Chinese Loess Plateau have been related to East Asian summer monsoon intensity and position, and could provide insights into future changes caused by global warming. Here, we present δC records of bulk organic matter since the Last Glacial Maximum(LGM) from 21 loess sections across the Loess Plateau. The δC values(range: –25‰ to –16‰) increased gradually both from the LGM to the mid-Holocene in each section and from northwest to southeast in each time interval. During the LGM, C biomass increased from40% in the southeast. The spatial pattern of C biomass in both the LGM and the mid-Holocene closely resembles that of modern warm-season precipitation, and thus can serve as a robust analog for the contemporary East Asian summer monsoon rain belt. Using the 10–20% isolines for C biomass in the cold LGM as a reference, we derived a minimum 300-km northwestward migration of the monsoon rain belt for the warm Holocene. Our results strongly support the prediction that Earth’s thermal equator will move northward in a warmer world. The southward displacement of the monsoon rain belt and the drying trend observed during the last few decades in northern China will soon reverse as global warming continues.