Orbital-scale global climatic changes during the late Quaternary are dominated by high-latitude influenced~100,000-year global ice-age cycles and monsoon influenced~23,000-year low-latitude hydroclimate variations.How...Orbital-scale global climatic changes during the late Quaternary are dominated by high-latitude influenced~100,000-year global ice-age cycles and monsoon influenced~23,000-year low-latitude hydroclimate variations.However,the shortage of highly-resolved land temperature records remains a limiting factor for achieving a comprehensive understanding of long-term low-latitude terrestrial climatic changes.Here,we report paired mean annual air temperature(MAAT)and monsoon intensity proxy records over the past 88,000 years from Lake Tengchongqinghai in southwestern China.While summer monsoon intensity follows the~23,000-year precession beat found also in previous studies,we identify previously unrecognized warm periods at 88,000-71,000 and 45,000-22,000 years ago,with 2-3℃amplitudes that are close to our recorded full glacial-interglacial range.Using advanced transient climate simulations and comparing with forcing factors,we find that these warm periods in our MAAT record probably depends on local annual mean insolation,which is controlled by Earth’s~41,000-year obliquity cycles and is anti-phased to annual mean insolation at high latitudes.The coincidence of our identified warm periods and intervals of high-frequent dated archaeological evidence highlights the importance of temperature on anatomically modern humans in Asia during the last glacial stage.展开更多
准确界定蒙山峨峪口砾石堆积堤的形成时代,对于探明其成因、澄清山东中低山丘陵第四纪冰川有无之争,是一个需要解决的科学问题。峨峪口堆积垄岗砾石组构、沉积构造、地貌组合等标志,均指向其为山洪泥石流堆积物,且为暴发频率极低、发展...准确界定蒙山峨峪口砾石堆积堤的形成时代,对于探明其成因、澄清山东中低山丘陵第四纪冰川有无之争,是一个需要解决的科学问题。峨峪口堆积垄岗砾石组构、沉积构造、地貌组合等标志,均指向其为山洪泥石流堆积物,且为暴发频率极低、发展周期较长的水石流或稀性泥石流堆积。其下伏第四纪沉积物OSL埋藏年龄和AMS14C年龄可作为砾石堆积堤形成时代的最老约束参考年龄,当地村民迁居此地的历史可作为最小约束参考年代。OSL测年结果为2.1~2.3 ka BP,AMS14C测年结果为951~1522 cal AD,证明砾石堆积堤为数百年前形成的历史泥石流遗迹。展开更多
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB40010200 and XDA2009000004)the Program of Global Change and Mitigation+1 种基金Ministry of Science and Technology of China(2016YFA0600502)the National Natural Science Foundation of China(41877293,41672162,41977381,and 41472315)。
文摘Orbital-scale global climatic changes during the late Quaternary are dominated by high-latitude influenced~100,000-year global ice-age cycles and monsoon influenced~23,000-year low-latitude hydroclimate variations.However,the shortage of highly-resolved land temperature records remains a limiting factor for achieving a comprehensive understanding of long-term low-latitude terrestrial climatic changes.Here,we report paired mean annual air temperature(MAAT)and monsoon intensity proxy records over the past 88,000 years from Lake Tengchongqinghai in southwestern China.While summer monsoon intensity follows the~23,000-year precession beat found also in previous studies,we identify previously unrecognized warm periods at 88,000-71,000 and 45,000-22,000 years ago,with 2-3℃amplitudes that are close to our recorded full glacial-interglacial range.Using advanced transient climate simulations and comparing with forcing factors,we find that these warm periods in our MAAT record probably depends on local annual mean insolation,which is controlled by Earth’s~41,000-year obliquity cycles and is anti-phased to annual mean insolation at high latitudes.The coincidence of our identified warm periods and intervals of high-frequent dated archaeological evidence highlights the importance of temperature on anatomically modern humans in Asia during the last glacial stage.
文摘准确界定蒙山峨峪口砾石堆积堤的形成时代,对于探明其成因、澄清山东中低山丘陵第四纪冰川有无之争,是一个需要解决的科学问题。峨峪口堆积垄岗砾石组构、沉积构造、地貌组合等标志,均指向其为山洪泥石流堆积物,且为暴发频率极低、发展周期较长的水石流或稀性泥石流堆积。其下伏第四纪沉积物OSL埋藏年龄和AMS14C年龄可作为砾石堆积堤形成时代的最老约束参考年龄,当地村民迁居此地的历史可作为最小约束参考年代。OSL测年结果为2.1~2.3 ka BP,AMS14C测年结果为951~1522 cal AD,证明砾石堆积堤为数百年前形成的历史泥石流遗迹。
