| DOI: | 10.5194/cp-9-1181-2013
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| Scopus记录号: | 2-s2.0-84883639624
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| 论文题名: | Abrupt shifts of the Sahara-Sahel boundary during Heinrich stadials |
| 作者: | Collins J.A.; Govin A.; Mulitza S.; Heslop D.; Zabel M.; Hartmann J.; Röhl U.; Wefer G.
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| 刊名: | Climate of the Past
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| ISSN: | 18149324
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| 出版年: | 2013
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| 卷: | 9, 期:3 | | 起始页码: | 1181
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| 结束页码: | 1191
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| 语种: | 英语
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| Scopus关键词: | boundary layer
; continental margin
; dune
; dust
; Heinrich event
; meridional circulation
; paleoclimate
; Pleistocene
; sea surface temperature
; sediment core
; timescale
; Atlantic Ocean
; Atlantic Ocean (North)
; Sahel [Sub-Saharan Africa]
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| 英文摘要: | Relict dune fields that are found as far south as 14° N in the modern-day African Sahel are testament to equatorward expansions of the Sahara desert during the Late Pleistocene. However, the discontinuous nature of dune records means that abrupt millennial-timescale climate events are not always resolved. High-resolution marine core studies have identified Heinrich stadials as the dustiest periods of the last glacial in West Africa although the spatial evolution of dust export on millennial timescales has so far not been investigated. We use the major-element composition of four high-resolution marine sediment cores to reconstruct the spatial extent of Saharan-dust versus river-sediment input to the continental margin from West Africa over the last 60 ka. This allows us to map the position of the sediment composition corresponding to the Sahara-Sahel boundary. Our records indicate that the Sahara-Sahel boundary reached its most southerly position (13° N) during Heinrich stadials and hence suggest that these were the periods when the sand dunes formed at 14° N on the continent. Heinrich stadials are associated with cold North Atlantic sea surface temperatures which appear to have triggered abrupt increases of aridity and wind strength in the Sahel. Our study illustrates the influence of the Atlantic meridional overturning circulation on the position of the Sahara-Sahel boundary and on global atmospheric dust loading. © Author(s) 2013. |
| 资助项目: | ARC, Australian Research Council
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/49386
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| Appears in Collections: | 气候变化与战略
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| Recommended Citation: | |
Collins J.A.,Govin A.,Mulitza S.,et al. Abrupt shifts of the Sahara-Sahel boundary during Heinrich stadials[J]. Climate of the Past,2013-01-01,9(3)
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