Late Quaternary deep stratification-climate coupling in the Southern Ocean: implications for changes in abyssal carbon storage
The Southern Ocean plays an important role in modulating Pleistocene atmospheric CO2 concentrations, but the underlying mechanisms are not yet fully understood. Here, we report the laser grain‐size distribution and Mn geochemical data of a 523 kyr‐long sediment record (core ANT30/P1‐02 off Prydz Bay...
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Online Access: | http://hdl.handle.net/2440/114927 https://doi.org/10.1002/2017GC007250 |
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ftunivadelaidedl:oai:digital.library.adelaide.edu.au:2440/114927 2023-12-24T10:10:19+01:00 Late Quaternary deep stratification-climate coupling in the Southern Ocean: implications for changes in abyssal carbon storage Wu, L. Wang, R. Xiao, W. Krijgsman, W. Li, Q. Ge, S. Ma, T. 2018 application/pdf http://hdl.handle.net/2440/114927 https://doi.org/10.1002/2017GC007250 en eng American Geophysical Union G3: Geochemistry, Geophysics, Geosystems: an electronic journal of the earth sciences, 2018; 19(2):379-395 1525-2027 http://hdl.handle.net/2440/114927 doi:10.1002/2017GC007250 © 2018. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. http://dx.doi.org/10.1002/2017gc007250 Meridional overturning circulation lower MOC circuit deep ventilation biological pump Journal article 2018 ftunivadelaidedl https://doi.org/10.1002/2017GC00725010.1002/2017gc007250 2023-11-27T23:18:03Z The Southern Ocean plays an important role in modulating Pleistocene atmospheric CO2 concentrations, but the underlying mechanisms are not yet fully understood. Here, we report the laser grain‐size distribution and Mn geochemical data of a 523 kyr‐long sediment record (core ANT30/P1‐02 off Prydz Bay; East Antarctica) to trace past physical changes in the deep Southern Ocean. The core sediments are predominantly composed of clay and silt‐sized material. Three grain size end‐members (EM) as well as three sensitive grain size classes (SC) were discerned, interpreted as Ice Rafted Debris (EM1 and SC1), and coarse (EM2 and SC2) and fine (EM3, SC3) materials deposited from bottom nepheloid layers, respectively. Ratios of EM2/(EM2 + EM3) and SC2/SC3 reveal changes in the local bottom current strength, which is related to the deep ocean diapycnal mixing rate, showing higher values during interglacial periods and lower values during glacial periods. MnO was enriched at each glacial termination, probably caused by abrupt elevations in Antarctic bottom water (AABW) formation rate. Lower AABW formation rate and reduced deep diapycnal mixing during glacial periods enhanced deep Southern Ocean stratification, contributing to glacial atmospheric CO2 drawdown. The elevated AABW formation and enhanced deep diapycnal mixing during glacial terminations alleviated such deep stratification, promoting deeply sequestered CO2 to outgas. Li Wu, Rujian Wang, Wenshen Xiao, Wout Krijgsman, Qianyu Li, Shulan Ge, Tong Ma Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Prydz Bay Southern Ocean The University of Adelaide: Digital Library Antarctic Southern Ocean East Antarctica Prydz Bay Geochemistry, Geophysics, Geosystems 19 2 379 395 |
institution |
Open Polar |
collection |
The University of Adelaide: Digital Library |
op_collection_id |
ftunivadelaidedl |
language |
English |
topic |
Meridional overturning circulation lower MOC circuit deep ventilation biological pump |
spellingShingle |
Meridional overturning circulation lower MOC circuit deep ventilation biological pump Wu, L. Wang, R. Xiao, W. Krijgsman, W. Li, Q. Ge, S. Ma, T. Late Quaternary deep stratification-climate coupling in the Southern Ocean: implications for changes in abyssal carbon storage |
topic_facet |
Meridional overturning circulation lower MOC circuit deep ventilation biological pump |
description |
The Southern Ocean plays an important role in modulating Pleistocene atmospheric CO2 concentrations, but the underlying mechanisms are not yet fully understood. Here, we report the laser grain‐size distribution and Mn geochemical data of a 523 kyr‐long sediment record (core ANT30/P1‐02 off Prydz Bay; East Antarctica) to trace past physical changes in the deep Southern Ocean. The core sediments are predominantly composed of clay and silt‐sized material. Three grain size end‐members (EM) as well as three sensitive grain size classes (SC) were discerned, interpreted as Ice Rafted Debris (EM1 and SC1), and coarse (EM2 and SC2) and fine (EM3, SC3) materials deposited from bottom nepheloid layers, respectively. Ratios of EM2/(EM2 + EM3) and SC2/SC3 reveal changes in the local bottom current strength, which is related to the deep ocean diapycnal mixing rate, showing higher values during interglacial periods and lower values during glacial periods. MnO was enriched at each glacial termination, probably caused by abrupt elevations in Antarctic bottom water (AABW) formation rate. Lower AABW formation rate and reduced deep diapycnal mixing during glacial periods enhanced deep Southern Ocean stratification, contributing to glacial atmospheric CO2 drawdown. The elevated AABW formation and enhanced deep diapycnal mixing during glacial terminations alleviated such deep stratification, promoting deeply sequestered CO2 to outgas. Li Wu, Rujian Wang, Wenshen Xiao, Wout Krijgsman, Qianyu Li, Shulan Ge, Tong Ma |
format |
Article in Journal/Newspaper |
author |
Wu, L. Wang, R. Xiao, W. Krijgsman, W. Li, Q. Ge, S. Ma, T. |
author_facet |
Wu, L. Wang, R. Xiao, W. Krijgsman, W. Li, Q. Ge, S. Ma, T. |
author_sort |
Wu, L. |
title |
Late Quaternary deep stratification-climate coupling in the Southern Ocean: implications for changes in abyssal carbon storage |
title_short |
Late Quaternary deep stratification-climate coupling in the Southern Ocean: implications for changes in abyssal carbon storage |
title_full |
Late Quaternary deep stratification-climate coupling in the Southern Ocean: implications for changes in abyssal carbon storage |
title_fullStr |
Late Quaternary deep stratification-climate coupling in the Southern Ocean: implications for changes in abyssal carbon storage |
title_full_unstemmed |
Late Quaternary deep stratification-climate coupling in the Southern Ocean: implications for changes in abyssal carbon storage |
title_sort |
late quaternary deep stratification-climate coupling in the southern ocean: implications for changes in abyssal carbon storage |
publisher |
American Geophysical Union |
publishDate |
2018 |
url |
http://hdl.handle.net/2440/114927 https://doi.org/10.1002/2017GC007250 |
geographic |
Antarctic Southern Ocean East Antarctica Prydz Bay |
geographic_facet |
Antarctic Southern Ocean East Antarctica Prydz Bay |
genre |
Antarc* Antarctic Antarctica East Antarctica Prydz Bay Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Prydz Bay Southern Ocean |
op_source |
http://dx.doi.org/10.1002/2017gc007250 |
op_relation |
G3: Geochemistry, Geophysics, Geosystems: an electronic journal of the earth sciences, 2018; 19(2):379-395 1525-2027 http://hdl.handle.net/2440/114927 doi:10.1002/2017GC007250 |
op_rights |
© 2018. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. |
op_doi |
https://doi.org/10.1002/2017GC00725010.1002/2017gc007250 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
19 |
container_issue |
2 |
container_start_page |
379 |
op_container_end_page |
395 |
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1786215018110386176 |