气候变化领域集成服务门户(CCPortal): The transient impact of the African monsoon on Plio-Pleistocene Mediterranean sediments

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DOI	10.5194/cp-17-331-2021
	The transient impact of the African monsoon on Plio-Pleistocene Mediterranean sediments
	De Boer B.; Peters M.; Lourens L.J.
发表日期	2021
ISSN	1814-9324
起始页码	265
结束页码	282
卷号	17 期号:1
英文摘要	Over the Plio-Pleistocene interval a strong linkage exists between northern African climate changes and the supply of dust over the surrounding oceans and continental runoff towards the Mediterranean Sea. Both these signatures in the sedimentary record are determined by orbital cycles influencing glacial variability on the one hand and northern African monsoon intensity on the other hand. In this paper, we use the intermediate-complexity model CLIMBER- 2 to simulate African climate during the Plio-Pleistocene between 3.2 and 2.3 million years ago (Ma) and compare our simulations with existing and new climate reconstructions. The CLIMBER-2 model is externally forced with atmospheric CO2 concentrations, ice sheet topography, and orbital variations, all of which strongly influence climate during the Pliocene and Pleistocene. Our simulations indicate that the records of northern Africa climate oscillate in phase with climatic precession. For the Earth's obliquity cycle, the time lag between the 41 000-year component in insolation forcing and the climatic response increased after inception of Northern Hemisphere (NH) glaciation around 2.8 Ma. To test the outcome of our simulations, we have put emphasis on the comparison between the simulated runoff of grid boxes encompassing the Sahara desert and the Sahel region and the sedimentary records of marine sediment cores from ODP Site 659 (Atlantic Ocean) and ODP Site 967 (Mediterranean). In this study we will show for the first time an extended Ti=Al record of Site 967 down to 3.2 Ma. This record strongly correlates with runoff in the Sahara and Sahel regions, whereas correlation with the dust record of Site 659 is moderate and slightly improves after NH ice sheet inception. We investigated the transient variability of the individual and combined contributions of the Sahel and Sahara regions and found significant transient behaviour overlapping the inception of NH ice sheets (2.8 Ma) and the Plio-Pleistocene transition (2.6 Ma). Prior to 2.8 Ma, a larger contribution from the Sahara region is required to explain the variability of Mediterranean dust input. After this transition, we found that a more equal contribution of the two regions is required, representing an increased influence of Sahel runoff and wet periods. © Author(s) 2021.
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183609
作者单位	Earth and Climate Cluster, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands; Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, Netherlands; United Experts cvba, Beringen, Belgium
推荐引用方式 GB/T 7714	De Boer B.,Peters M.,Lourens L.J.. The transient impact of the African monsoon on Plio-Pleistocene Mediterranean sediments[J],2021,17(1).
APA	De Boer B.,Peters M.,&Lourens L.J..(2021).The transient impact of the African monsoon on Plio-Pleistocene Mediterranean sediments.Climate of the Past,17(1).
MLA	De Boer B.,et al."The transient impact of the African monsoon on Plio-Pleistocene Mediterranean sediments".Climate of the Past 17.1(2021).