North African humid periods over the past 800,000 years
Abstract The Sahara region has experienced periodic wet periods over the Quaternary and beyond. These North African Humid Periods (NAHPs) are astronomically paced by precession which controls the intensity of the African monsoon system. However, most climate models cannot reconcile the magnitude of...
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ftdoajarticles:oai:doaj.org/article:001b0d7e59074a0eba58b67c55bb1955 2023-10-09T21:52:24+02:00 North African humid periods over the past 800,000 years Edward Armstrong Miikka Tallavaara Peter O. Hopcroft Paul J. Valdes 2023-09-01T00:00:00Z https://doi.org/10.1038/s41467-023-41219-4 https://doaj.org/article/001b0d7e59074a0eba58b67c55bb1955 EN eng Nature Portfolio https://doi.org/10.1038/s41467-023-41219-4 https://doaj.org/toc/2041-1723 doi:10.1038/s41467-023-41219-4 2041-1723 https://doaj.org/article/001b0d7e59074a0eba58b67c55bb1955 Nature Communications, Vol 14, Iss 1, Pp 1-11 (2023) Science Q article 2023 ftdoajarticles https://doi.org/10.1038/s41467-023-41219-4 2023-09-17T00:39:25Z Abstract The Sahara region has experienced periodic wet periods over the Quaternary and beyond. These North African Humid Periods (NAHPs) are astronomically paced by precession which controls the intensity of the African monsoon system. However, most climate models cannot reconcile the magnitude of these events and so the driving mechanisms remain poorly constrained. Here, we utilise a recently developed version of the HadCM3B coupled climate model that simulates 20 NAHPs over the past 800 kyr which have good agreement with NAHPs identified in proxy data. Our results show that precession determines NAHP pacing, but we identify that their amplitude is strongly linked to eccentricity via its control over ice sheet extent. During glacial periods, enhanced ice-albedo driven cooling suppresses NAHP amplitude at precession minima, when humid conditions would otherwise be expected. This highlights the importance of both precession and eccentricity, and the role of high latitude processes in determining the timing and amplitude of the NAHPs. This may have implications for the out of Africa dispersal of plants and animals throughout the Quaternary. Article in Journal/Newspaper Ice Sheet Directory of Open Access Journals: DOAJ Articles Nature Communications 14 1 |
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Science Q Edward Armstrong Miikka Tallavaara Peter O. Hopcroft Paul J. Valdes North African humid periods over the past 800,000 years |
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Science Q |
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Abstract The Sahara region has experienced periodic wet periods over the Quaternary and beyond. These North African Humid Periods (NAHPs) are astronomically paced by precession which controls the intensity of the African monsoon system. However, most climate models cannot reconcile the magnitude of these events and so the driving mechanisms remain poorly constrained. Here, we utilise a recently developed version of the HadCM3B coupled climate model that simulates 20 NAHPs over the past 800 kyr which have good agreement with NAHPs identified in proxy data. Our results show that precession determines NAHP pacing, but we identify that their amplitude is strongly linked to eccentricity via its control over ice sheet extent. During glacial periods, enhanced ice-albedo driven cooling suppresses NAHP amplitude at precession minima, when humid conditions would otherwise be expected. This highlights the importance of both precession and eccentricity, and the role of high latitude processes in determining the timing and amplitude of the NAHPs. This may have implications for the out of Africa dispersal of plants and animals throughout the Quaternary. |
format |
Article in Journal/Newspaper |
author |
Edward Armstrong Miikka Tallavaara Peter O. Hopcroft Paul J. Valdes |
author_facet |
Edward Armstrong Miikka Tallavaara Peter O. Hopcroft Paul J. Valdes |
author_sort |
Edward Armstrong |
title |
North African humid periods over the past 800,000 years |
title_short |
North African humid periods over the past 800,000 years |
title_full |
North African humid periods over the past 800,000 years |
title_fullStr |
North African humid periods over the past 800,000 years |
title_full_unstemmed |
North African humid periods over the past 800,000 years |
title_sort |
north african humid periods over the past 800,000 years |
publisher |
Nature Portfolio |
publishDate |
2023 |
url |
https://doi.org/10.1038/s41467-023-41219-4 https://doaj.org/article/001b0d7e59074a0eba58b67c55bb1955 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Nature Communications, Vol 14, Iss 1, Pp 1-11 (2023) |
op_relation |
https://doi.org/10.1038/s41467-023-41219-4 https://doaj.org/toc/2041-1723 doi:10.1038/s41467-023-41219-4 2041-1723 https://doaj.org/article/001b0d7e59074a0eba58b67c55bb1955 |
op_doi |
https://doi.org/10.1038/s41467-023-41219-4 |
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Nature Communications |
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14 |
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1 |
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1779315573014921216 |