Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene

Marine sediment records from a series of core sites along the northwest African margin show a sudden increase in North Atlantic dust deposition at about 5 ka BP that has been associated with an abrupt end of the African Humid Period (AHP). To assess the causes of the abrupt shift in North Atlantic d...

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Published in:Climate of the Past
Main Authors: Egerer, Sabine, Claussen, Martin, Reick, Christian
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2018
Subjects:
Online Access:https://doi.org/10.5194/cp-14-1051-2018
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spelling ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00005305 2023-05-15T17:28:42+02:00 Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene Egerer, Sabine Claussen, Martin Reick, Christian 2018-07 electronic https://doi.org/10.5194/cp-14-1051-2018 https://noa.gwlb.de/receive/cop_mods_00005305 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00005262/cp-14-1051-2018.pdf https://cp.copernicus.org/articles/14/1051/2018/cp-14-1051-2018.pdf eng eng Copernicus Publications Climate of the Past -- http://www.copernicus.org/EGU/cp/cp/published_papers.html -- http://www.bibliothek.uni-regensburg.de/ezeit/?2217985 -- 1814-9332 https://doi.org/10.5194/cp-14-1051-2018 https://noa.gwlb.de/receive/cop_mods_00005305 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00005262/cp-14-1051-2018.pdf https://cp.copernicus.org/articles/14/1051/2018/cp-14-1051-2018.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2018 ftnonlinearchiv https://doi.org/10.5194/cp-14-1051-2018 2022-02-08T22:59:39Z Marine sediment records from a series of core sites along the northwest African margin show a sudden increase in North Atlantic dust deposition at about 5 ka BP that has been associated with an abrupt end of the African Humid Period (AHP). To assess the causes of the abrupt shift in North Atlantic dust deposition, we explore changes in the Holocene dust cycle and in North African climate and landscape by performing several time slice simulations from 8 ka BP until the preindustrial era. To do this, we use the coupled aerosol–climate model ECHAM6–HAM2 including dynamic vegetation and interactive dust, wherein ocean conditions and lake surface area are prescribed for each time slice. We find a rapid increase in simulated dust deposition between 6 and 4 ka BP that is fairly consistent with the abrupt change in marine sediment records at around 20∘ N close to the northwest African margin. At more northern and more remote cores, a significant change in dust deposition is noticeable roughly between 6 and 2 ka BP in the simulations as well as in the records, but the change is less sharp compared to the near-margin core sites. The rapid change in simulated dust deposition is caused by a rapid increase in simulated dust emissions in the western Sahara, where the main dust sources for dust transport towards the North Atlantic are located. The sudden increase in dust emissions in the western Sahara is according to our simulations a consequence of a fast decline of vegetation cover from 22 to 18∘ N that might occur due to vegetation–climate feedbacks or due to the existence of a precipitation threshold on vegetation growth. Additionally, the prescribed gradual reduction of lake area enforces accelerated dust release as highly productive dust sources are uncovered. Concurrently with the continental drying, surface winds in the western Sahara are accelerated. Changes in the Saharan landscape and dust emissions south of 18∘ N and in the eastern Sahara play a minor role in driving the dynamics of North Atlantic dust deposition at the core sites. Our study identifies spatial and temporal heterogeneity in the transition of the North African landscape. As a consequence, implications from local data records on large-scale climate have to be treated with caution. Article in Journal/Newspaper North Atlantic Niedersächsisches Online-Archiv NOA Climate of the Past 14 7 1051 1066
institution Open Polar
collection Niedersächsisches Online-Archiv NOA
op_collection_id ftnonlinearchiv
language English
topic article
Verlagsveröffentlichung
spellingShingle article
Verlagsveröffentlichung
Egerer, Sabine
Claussen, Martin
Reick, Christian
Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene
topic_facet article
Verlagsveröffentlichung
description Marine sediment records from a series of core sites along the northwest African margin show a sudden increase in North Atlantic dust deposition at about 5 ka BP that has been associated with an abrupt end of the African Humid Period (AHP). To assess the causes of the abrupt shift in North Atlantic dust deposition, we explore changes in the Holocene dust cycle and in North African climate and landscape by performing several time slice simulations from 8 ka BP until the preindustrial era. To do this, we use the coupled aerosol–climate model ECHAM6–HAM2 including dynamic vegetation and interactive dust, wherein ocean conditions and lake surface area are prescribed for each time slice. We find a rapid increase in simulated dust deposition between 6 and 4 ka BP that is fairly consistent with the abrupt change in marine sediment records at around 20∘ N close to the northwest African margin. At more northern and more remote cores, a significant change in dust deposition is noticeable roughly between 6 and 2 ka BP in the simulations as well as in the records, but the change is less sharp compared to the near-margin core sites. The rapid change in simulated dust deposition is caused by a rapid increase in simulated dust emissions in the western Sahara, where the main dust sources for dust transport towards the North Atlantic are located. The sudden increase in dust emissions in the western Sahara is according to our simulations a consequence of a fast decline of vegetation cover from 22 to 18∘ N that might occur due to vegetation–climate feedbacks or due to the existence of a precipitation threshold on vegetation growth. Additionally, the prescribed gradual reduction of lake area enforces accelerated dust release as highly productive dust sources are uncovered. Concurrently with the continental drying, surface winds in the western Sahara are accelerated. Changes in the Saharan landscape and dust emissions south of 18∘ N and in the eastern Sahara play a minor role in driving the dynamics of North Atlantic dust deposition at the core sites. Our study identifies spatial and temporal heterogeneity in the transition of the North African landscape. As a consequence, implications from local data records on large-scale climate have to be treated with caution.
format Article in Journal/Newspaper
author Egerer, Sabine
Claussen, Martin
Reick, Christian
author_facet Egerer, Sabine
Claussen, Martin
Reick, Christian
author_sort Egerer, Sabine
title Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene
title_short Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene
title_full Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene
title_fullStr Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene
title_full_unstemmed Rapid increase in simulated North Atlantic dust deposition due to fast change of northwest African landscape during the Holocene
title_sort rapid increase in simulated north atlantic dust deposition due to fast change of northwest african landscape during the holocene
publisher Copernicus Publications
publishDate 2018
url https://doi.org/10.5194/cp-14-1051-2018
https://noa.gwlb.de/receive/cop_mods_00005305
https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00005262/cp-14-1051-2018.pdf
https://cp.copernicus.org/articles/14/1051/2018/cp-14-1051-2018.pdf
genre North Atlantic
genre_facet North Atlantic
op_relation Climate of the Past -- http://www.copernicus.org/EGU/cp/cp/published_papers.html -- http://www.bibliothek.uni-regensburg.de/ezeit/?2217985 -- 1814-9332
https://doi.org/10.5194/cp-14-1051-2018
https://noa.gwlb.de/receive/cop_mods_00005305
https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00005262/cp-14-1051-2018.pdf
https://cp.copernicus.org/articles/14/1051/2018/cp-14-1051-2018.pdf
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container_title Climate of the Past
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