Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax δD and δ^(13)C
To reconstruct variability of the West African monsoon and associated vegetation changes on precessional and millennial time scales, we analyzed a marine sediment core from the continental slope off Senegal spanning the past 44,000 years (44 ka). We used the stable hydrogen isotopic composition (δD...
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ftcaltechauth:oai:authors.library.caltech.edu:ams5s-cg161 2024-09-15T18:24:25+00:00 Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax δD and δ^(13)C Niedermeyer, Eva M. Schefuß, Enno Sessions, Alex L. Mulitza, Stefan Mollenhauer, Gesine Schulz, Michael Wefer, Gerold 2010-11 https://doi.org/10.1016/j.quascirev.2010.06.039 unknown Elsevier https://doi.org/10.1016/j.quascirev.2010.06.039 oai:authors.library.caltech.edu:ams5s-cg161 eprintid:21276 resolverid:CaltechAUTHORS:20101209-121741039 info:eu-repo/semantics/closedAccess Other Quaternary Science Reviews, 29(23-24), 2996-3005, (2010-11) info:eu-repo/semantics/article 2010 ftcaltechauth https://doi.org/10.1016/j.quascirev.2010.06.039 2024-08-06T15:35:03Z To reconstruct variability of the West African monsoon and associated vegetation changes on precessional and millennial time scales, we analyzed a marine sediment core from the continental slope off Senegal spanning the past 44,000 years (44 ka). We used the stable hydrogen isotopic composition (δD) of individual terrestrial plant wax n-alkanes as a proxy for past rainfall variability. The abundance and stable carbon isotopic composition (δ^(13)C) of the same compounds were analyzed to assess changes in vegetation composition (C_(3)/C_(4) plants) and density. The δD record reveals two wet periods that coincide with local maximum summer insolation from 38 to 28 ka and 15 to 4 ka and that are separated by a less wet period during minimum summer insolation. Our data indicate that rainfall intensity during the rainy season throughout both wet humid periods was similar, whereas the length of the rainy season was presumably shorter during the last glacial than during the Holocene. Additional dry intervals are identified that coincide with North Atlantic Heinrich stadials and the Younger Dryas interval, indicating that the West African monsoon over tropical northwest Africa is linked to both insolation forcing and high-latitude climate variability. The δ^(13)C record indicates that vegetation of the western Sahel was consistently dominated by C_4 plants during the past 44 ka, whereas C_(3)-type vegetation increased during the Holocene. Moreover, we observe a gradual ending of the Holocene humid period together with unchanging ratio of C_3 to C_4 plants, indicating that an abrupt aridification due to vegetation feedbacks is not a general characteristic of this time interval. © 2010 Elsevier Ltd. Received 11 September 2009; revised 24 June 2010; accepted 25 June 2010. Available online 5 August 2010. This work was funded by the German Science Foundation (DFG) through the Research Center/Excellence Cluster "The Ocean in the Earth System" at MARUM – Center for Marine Environmental Sciences, University of Bremen and ... Article in Journal/Newspaper North Atlantic Caltech Authors (California Institute of Technology) Quaternary Science Reviews 29 23-24 2996 3005 |
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To reconstruct variability of the West African monsoon and associated vegetation changes on precessional and millennial time scales, we analyzed a marine sediment core from the continental slope off Senegal spanning the past 44,000 years (44 ka). We used the stable hydrogen isotopic composition (δD) of individual terrestrial plant wax n-alkanes as a proxy for past rainfall variability. The abundance and stable carbon isotopic composition (δ^(13)C) of the same compounds were analyzed to assess changes in vegetation composition (C_(3)/C_(4) plants) and density. The δD record reveals two wet periods that coincide with local maximum summer insolation from 38 to 28 ka and 15 to 4 ka and that are separated by a less wet period during minimum summer insolation. Our data indicate that rainfall intensity during the rainy season throughout both wet humid periods was similar, whereas the length of the rainy season was presumably shorter during the last glacial than during the Holocene. Additional dry intervals are identified that coincide with North Atlantic Heinrich stadials and the Younger Dryas interval, indicating that the West African monsoon over tropical northwest Africa is linked to both insolation forcing and high-latitude climate variability. The δ^(13)C record indicates that vegetation of the western Sahel was consistently dominated by C_4 plants during the past 44 ka, whereas C_(3)-type vegetation increased during the Holocene. Moreover, we observe a gradual ending of the Holocene humid period together with unchanging ratio of C_3 to C_4 plants, indicating that an abrupt aridification due to vegetation feedbacks is not a general characteristic of this time interval. © 2010 Elsevier Ltd. Received 11 September 2009; revised 24 June 2010; accepted 25 June 2010. Available online 5 August 2010. This work was funded by the German Science Foundation (DFG) through the Research Center/Excellence Cluster "The Ocean in the Earth System" at MARUM – Center for Marine Environmental Sciences, University of Bremen and ... |
format |
Article in Journal/Newspaper |
author |
Niedermeyer, Eva M. Schefuß, Enno Sessions, Alex L. Mulitza, Stefan Mollenhauer, Gesine Schulz, Michael Wefer, Gerold |
spellingShingle |
Niedermeyer, Eva M. Schefuß, Enno Sessions, Alex L. Mulitza, Stefan Mollenhauer, Gesine Schulz, Michael Wefer, Gerold Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax δD and δ^(13)C |
author_facet |
Niedermeyer, Eva M. Schefuß, Enno Sessions, Alex L. Mulitza, Stefan Mollenhauer, Gesine Schulz, Michael Wefer, Gerold |
author_sort |
Niedermeyer, Eva M. |
title |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax δD and δ^(13)C |
title_short |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax δD and δ^(13)C |
title_full |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax δD and δ^(13)C |
title_fullStr |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax δD and δ^(13)C |
title_full_unstemmed |
Orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western African Sahel: insights from individual plant wax δD and δ^(13)C |
title_sort |
orbital- and millennial-scale changes in the hydrologic cycle and vegetation in the western african sahel: insights from individual plant wax î´d and î´^(13)c |
publisher |
Elsevier |
publishDate |
2010 |
url |
https://doi.org/10.1016/j.quascirev.2010.06.039 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Quaternary Science Reviews, 29(23-24), 2996-3005, (2010-11) |
op_relation |
https://doi.org/10.1016/j.quascirev.2010.06.039 oai:authors.library.caltech.edu:ams5s-cg161 eprintid:21276 resolverid:CaltechAUTHORS:20101209-121741039 |
op_rights |
info:eu-repo/semantics/closedAccess Other |
op_doi |
https://doi.org/10.1016/j.quascirev.2010.06.039 |
container_title |
Quaternary Science Reviews |
container_volume |
29 |
container_issue |
23-24 |
container_start_page |
2996 |
op_container_end_page |
3005 |
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1810464769642070016 |