Decoupled warming and monsoon precipitation in East Asia over the last deglaciation
Decoupled warming and monsoon precipitation in East Asia over the last deglaciation
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DOI：
10.1016/j.epsl.2010.11.010
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发表时间：
2011-01-03
影响因子：
5.3
通讯作者：
Damste, Jaap S. Sinninghe
中科院分区：
文献类型：
--
作者：
Peterse, Francien;Prins, Maarten A.;Damste, Jaap S. Sinninghe
我们对东亚大陆气候演变的认识主要基于黄土-古土壤序列和基于中国几个洞穴石笋氧同位素(O-18)的夏季风降水重建。根据这些记录，认为东亚夏季风(EASM)降水一般跟随北半球(NH)夏季太阳活动。然而，关于东亚大陆冰川消融变暖的幅度和时间，人们知之甚少。在这项研究中，我们根据芒山黄土高原黄土-古土壤序列中土壤细菌的化石支链四醚膜脂的分布，重建了近34000年以来中国中部的大陆气温。结果表明，夏季气温与夏季日照高度呈同相变化，与南极、南非、南美洲等地的其他大陆记录相比，19KYR BP左右的降冰期开始变暖的时间是平行的。气温从升温开始时的-IS C上升到全新世早期的最高-27摄氏度(类似于12KYR BP)，这与从花粉和植硅体数据推断的温度上升以及中国中部的永久冻土界限一致。与黄土-古土壤替代记录和石笋5180记录相比较，EASM降水的增强滞后于去冰期增温约3KYR。此外，由于夏季风降水的大幅增加，黄土沉积物中强烈的土壤形成只开始于12KYR BP左右(约7KYR滞后)。因此，我们的结果表明，EASM降水的增强明显滞后于去冰期变暖和夏季NH日照，这可能有助于更好地理解控制冰期终止的机制。(C)2010爱思唯尔B.V.保留所有权利。
Our understanding of the continental climate development in East Asia is mainly based on loess-paleosol sequences and summer monsoon precipitation reconstructions based on oxygen isotopes (delta O-18) of stalagmites from several Chinese caves. Based on these records, it is thought that East Asian Summer Monsoon (EASM) precipitation generally follows Northern Hemisphere (NH) summer insolation. However, not much is known about the magnitude and timing of deglacial warming on the East Asian continent. In this study we reconstruct continental air temperatures for central China covering the last 34,000 yr, based on the distribution of fossil branched tetraether membrane lipids of soil bacteria in a loess-paleosol sequence from the Mangshan loess plateau. The results indicate that air temperature varied in phase with NH summer insolation, and that the onset of deglacial warming at similar to 19 kyr BP is parallel in timing with other continental records from e.g. Antarctica, southern Africa and South-America. The air temperature increased from-IS C at the onset of the warming to a maximum of -27 degrees C in the early Holocene (similar to 12 kyr BP), in agreement with the temperature increase inferred from e.g. pollen and phytolith data, and permafrost limits in central China. Comparison of the tetraether membrane lipid-derived temperature record with loess-paleosol proxy records and stalagmite 5180 records shows that the strengthening of EASM precipitation lagged that of deglacial warming by ca. 3 kyr. Moreover, intense soil formation in the loess deposits, caused by substantial increases in summer monsoon precipitation, only started around 12 kyr BP (ca. 7 kyr lag). Our results thus show that the intensification of EASM precipitation unambiguously lagged deglacial warming and NH summer insolation, and may contribute to a better understanding of the mechanisms controlling ice age terminations. (C) 2010 Elsevier B.V. All rights reserved.