From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates
The current-climate Indian monsoon is known to boost biological productivity in the Arabian Sea. This paradigm has been extensively used to reconstruct past monsoon variability from palaeo-proxies indicative of changes in surface productivity. Here, we test this paradigm by simulating changes in mar...
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ftarchimer:oai:archimer.ifremer.fr:53146 2023-05-15T16:41:21+02:00 From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates Le Mezo, Priscilla Beaufort, Luc Bopp, Laurent Braconnot, Pascale Kageyama, Masa 2017-07-04 application/pdf https://archimer.ifremer.fr/doc/00420/53146/55345.pdf https://archimer.ifremer.fr/doc/00420/53146/55346.pdf https://doi.org/10.5194/cp-13-759-2017 https://archimer.ifremer.fr/doc/00420/53146/ eng eng Copernicus Gesellschaft Mbh https://archimer.ifremer.fr/doc/00420/53146/55345.pdf https://archimer.ifremer.fr/doc/00420/53146/55346.pdf doi:10.5194/cp-13-759-2017 https://archimer.ifremer.fr/doc/00420/53146/ Author(s) 2017. This work is distributed under the Creative Commons Attribution 3.0 License. info:eu-repo/semantics/openAccess restricted use CC-BY Climate Of The Past (1814-9324) (Copernicus Gesellschaft Mbh), 2017-07-04 , Vol. 13 , N. 7 , P. 759-778 text Publication info:eu-repo/semantics/article 2017 ftarchimer https://doi.org/10.5194/cp-13-759-2017 2021-09-23T20:30:24Z The current-climate Indian monsoon is known to boost biological productivity in the Arabian Sea. This paradigm has been extensively used to reconstruct past monsoon variability from palaeo-proxies indicative of changes in surface productivity. Here, we test this paradigm by simulating changes in marine primary productivity for eight contrasted climates from the last glacial-interglacial cycle. We show that there is no straightforward correlation between bo-real summer productivity of the Arabian Sea and summer monsoon strength across the different simulated climates. Locally, productivity is fuelled by nutrient supply driven by Ekman dynamics. Upward transport of nutrients is modulated by a combination of alongshore wind stress intensity, which drives coastal upwelling, and by a positive wind stress curl to the west of the jet axis resulting in upward Ekman pumping. To the east of the jet axis there is however a strong downward Ekman pumping due to a negative wind stress curl. Consequently, changes in coastal along-shore stress and/ or curl depend on both the jet intensity and position. The jet position is constrained by the Indian summer monsoon pattern, which in turn is influenced by the astronomical parameters and the ice sheet cover. The astronomical parameters are indeed shown to impact wind stress intensity in the Arabian Sea through large-scale changes in the meridional gradient of upper-tropospheric temperature. However, both the astronomical parameters and the ice sheets affect the pattern of wind stress curl through the position of the sea level depression barycentre over the monsoon region (20-150 degrees W, 30 degrees S-60 degrees N). The combined changes in monsoon intensity and pattern lead to some higher glacial productivity during the summer season, in agreement with some palaeo-productivity reconstructions. Article in Journal/Newspaper Ice Sheet Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Indian Climate of the Past 13 7 759 778 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
description |
The current-climate Indian monsoon is known to boost biological productivity in the Arabian Sea. This paradigm has been extensively used to reconstruct past monsoon variability from palaeo-proxies indicative of changes in surface productivity. Here, we test this paradigm by simulating changes in marine primary productivity for eight contrasted climates from the last glacial-interglacial cycle. We show that there is no straightforward correlation between bo-real summer productivity of the Arabian Sea and summer monsoon strength across the different simulated climates. Locally, productivity is fuelled by nutrient supply driven by Ekman dynamics. Upward transport of nutrients is modulated by a combination of alongshore wind stress intensity, which drives coastal upwelling, and by a positive wind stress curl to the west of the jet axis resulting in upward Ekman pumping. To the east of the jet axis there is however a strong downward Ekman pumping due to a negative wind stress curl. Consequently, changes in coastal along-shore stress and/ or curl depend on both the jet intensity and position. The jet position is constrained by the Indian summer monsoon pattern, which in turn is influenced by the astronomical parameters and the ice sheet cover. The astronomical parameters are indeed shown to impact wind stress intensity in the Arabian Sea through large-scale changes in the meridional gradient of upper-tropospheric temperature. However, both the astronomical parameters and the ice sheets affect the pattern of wind stress curl through the position of the sea level depression barycentre over the monsoon region (20-150 degrees W, 30 degrees S-60 degrees N). The combined changes in monsoon intensity and pattern lead to some higher glacial productivity during the summer season, in agreement with some palaeo-productivity reconstructions. |
format |
Article in Journal/Newspaper |
author |
Le Mezo, Priscilla Beaufort, Luc Bopp, Laurent Braconnot, Pascale Kageyama, Masa |
spellingShingle |
Le Mezo, Priscilla Beaufort, Luc Bopp, Laurent Braconnot, Pascale Kageyama, Masa From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates |
author_facet |
Le Mezo, Priscilla Beaufort, Luc Bopp, Laurent Braconnot, Pascale Kageyama, Masa |
author_sort |
Le Mezo, Priscilla |
title |
From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates |
title_short |
From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates |
title_full |
From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates |
title_fullStr |
From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates |
title_full_unstemmed |
From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates |
title_sort |
from monsoon to marine productivity in the arabian sea: insights from glacial and interglacial climates |
publisher |
Copernicus Gesellschaft Mbh |
publishDate |
2017 |
url |
https://archimer.ifremer.fr/doc/00420/53146/55345.pdf https://archimer.ifremer.fr/doc/00420/53146/55346.pdf https://doi.org/10.5194/cp-13-759-2017 https://archimer.ifremer.fr/doc/00420/53146/ |
long_lat |
ENVELOPE(-63.071,-63.071,-70.797,-70.797) |
geographic |
Curl Indian |
geographic_facet |
Curl Indian |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Climate Of The Past (1814-9324) (Copernicus Gesellschaft Mbh), 2017-07-04 , Vol. 13 , N. 7 , P. 759-778 |
op_relation |
https://archimer.ifremer.fr/doc/00420/53146/55345.pdf https://archimer.ifremer.fr/doc/00420/53146/55346.pdf doi:10.5194/cp-13-759-2017 https://archimer.ifremer.fr/doc/00420/53146/ |
op_rights |
Author(s) 2017. This work is distributed under the Creative Commons Attribution 3.0 License. info:eu-repo/semantics/openAccess restricted use |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/cp-13-759-2017 |
container_title |
Climate of the Past |
container_volume |
13 |
container_issue |
7 |
container_start_page |
759 |
op_container_end_page |
778 |
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1766031781454151680 |