Thorium isotopes in the Southeast Atlantic Ocean: Tracking scavenging during water mass mixing along neutral density surfaces

Matthieu Roy-Barman; François Thil; Louise Bordier; Arnaud Dapoigny; Lorna Foliot; Sophie Ayrault; François Lacan; Catherine Jeandel; Catherine Pradoux; Ester Garcia-Solsona

doi:10.1016/j.dsr.2019.05.002

Thorium isotopes in the Southeast Atlantic Ocean: Tracking scavenging during water mass mixing along neutral density surfaces

Matthieu Roy-Barman, François Thil, Louise Bordier, Arnaud Dapoigny, Lorna Foliot, Sophie Ayrault, François Lacan, Catherine Jeandel, Catherine Pradoux, Ester Garcia-Solsona

Department of Physics

Research output: Contribution to journal › Article › Research

5 Citations (Scopus)

Abstract

© 2019 Elsevier Ltd The distributions of dissolved and particulate thorium isotopes (230Th and 232Th) were established in samples from the BONUS GoodHope (BGH) IPY-GEOTRACES cruise in the SE Atlantic sector of the Southern Ocean (36°S-13°E to 57°S-0°, Feb.–Mar. 2008). The distribution of total (dissolved + particulate) 232Th is dominated by the inputs from continental margins. The non-linear profiles of dissolved 230Th are interpreted as due to the southward upwelling of the isopycnal surfaces. However, total 230Th and 232Th versus salinity plots illustrate departures from binary mixing and provides evidence for non-conservative behavior of both isotopes along the section. We propose a model for total 230Th and 232Th scavenging and mixing along isopycnal surfaces. We use this model to estimate particle settling speeds and isopycnal eddy diffusion coefficients along the BGH section. Data-model comparison suggests particle settling velocities in the range of 400–700 m/y and isopycnal eddy diffusivity of the order of 2000 m2/s.

Original language	English
Article number	103042
Journal	Deep-Sea Research Part I: Oceanographic Research Papers
Volume	149
DOIs	https://doi.org/10.1016/j.dsr.2019.05.002
Publication status	Published - 1 Jul 2019

Keywords

Atlantic
Isopycnal mixing
Marine particles
Southern ocean
Thorium isotopes

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.dsr.2019.05.002

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Roy-Barman, M., Thil, F., Bordier, L., Dapoigny, A., Foliot, L., Ayrault, S., Lacan, F., Jeandel, C., Pradoux, C., & Garcia-Solsona, E. (2019). Thorium isotopes in the Southeast Atlantic Ocean: Tracking scavenging during water mass mixing along neutral density surfaces. Deep-Sea Research Part I: Oceanographic Research Papers, 149, [103042]. https://doi.org/10.1016/j.dsr.2019.05.002

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title = "Thorium isotopes in the Southeast Atlantic Ocean: Tracking scavenging during water mass mixing along neutral density surfaces",

abstract = "{\textcopyright} 2019 Elsevier Ltd The distributions of dissolved and particulate thorium isotopes (230Th and 232Th) were established in samples from the BONUS GoodHope (BGH) IPY-GEOTRACES cruise in the SE Atlantic sector of the Southern Ocean (36°S-13°E to 57°S-0°, Feb.–Mar. 2008). The distribution of total (dissolved + particulate) 232Th is dominated by the inputs from continental margins. The non-linear profiles of dissolved 230Th are interpreted as due to the southward upwelling of the isopycnal surfaces. However, total 230Th and 232Th versus salinity plots illustrate departures from binary mixing and provides evidence for non-conservative behavior of both isotopes along the section. We propose a model for total 230Th and 232Th scavenging and mixing along isopycnal surfaces. We use this model to estimate particle settling speeds and isopycnal eddy diffusion coefficients along the BGH section. Data-model comparison suggests particle settling velocities in the range of 400–700 m/y and isopycnal eddy diffusivity of the order of 2000 m2/s.",

keywords = "Atlantic, Isopycnal mixing, Marine particles, Southern ocean, Thorium isotopes",

author = "Matthieu Roy-Barman and Fran{\c c}ois Thil and Louise Bordier and Arnaud Dapoigny and Lorna Foliot and Sophie Ayrault and Fran{\c c}ois Lacan and Catherine Jeandel and Catherine Pradoux and Ester Garcia-Solsona",

year = "2019",

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doi = "10.1016/j.dsr.2019.05.002",

language = "English",

volume = "149",

journal = "Deep-Sea Research Part I: Oceanographic Research Papers",

issn = "0967-0637",

publisher = "Elsevier Limited",

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Roy-Barman, M, Thil, F, Bordier, L, Dapoigny, A, Foliot, L, Ayrault, S, Lacan, F, Jeandel, C, Pradoux, C & Garcia-Solsona, E 2019, 'Thorium isotopes in the Southeast Atlantic Ocean: Tracking scavenging during water mass mixing along neutral density surfaces', Deep-Sea Research Part I: Oceanographic Research Papers, vol. 149, 103042. https://doi.org/10.1016/j.dsr.2019.05.002

TY - JOUR

T1 - Thorium isotopes in the Southeast Atlantic Ocean: Tracking scavenging during water mass mixing along neutral density surfaces

AU - Roy-Barman, Matthieu

AU - Thil, François

AU - Bordier, Louise

AU - Dapoigny, Arnaud

AU - Foliot, Lorna

AU - Ayrault, Sophie

AU - Lacan, François

AU - Jeandel, Catherine

AU - Pradoux, Catherine

AU - Garcia-Solsona, Ester

PY - 2019/7/1

Y1 - 2019/7/1

N2 - © 2019 Elsevier Ltd The distributions of dissolved and particulate thorium isotopes (230Th and 232Th) were established in samples from the BONUS GoodHope (BGH) IPY-GEOTRACES cruise in the SE Atlantic sector of the Southern Ocean (36°S-13°E to 57°S-0°, Feb.–Mar. 2008). The distribution of total (dissolved + particulate) 232Th is dominated by the inputs from continental margins. The non-linear profiles of dissolved 230Th are interpreted as due to the southward upwelling of the isopycnal surfaces. However, total 230Th and 232Th versus salinity plots illustrate departures from binary mixing and provides evidence for non-conservative behavior of both isotopes along the section. We propose a model for total 230Th and 232Th scavenging and mixing along isopycnal surfaces. We use this model to estimate particle settling speeds and isopycnal eddy diffusion coefficients along the BGH section. Data-model comparison suggests particle settling velocities in the range of 400–700 m/y and isopycnal eddy diffusivity of the order of 2000 m2/s.

AB - © 2019 Elsevier Ltd The distributions of dissolved and particulate thorium isotopes (230Th and 232Th) were established in samples from the BONUS GoodHope (BGH) IPY-GEOTRACES cruise in the SE Atlantic sector of the Southern Ocean (36°S-13°E to 57°S-0°, Feb.–Mar. 2008). The distribution of total (dissolved + particulate) 232Th is dominated by the inputs from continental margins. The non-linear profiles of dissolved 230Th are interpreted as due to the southward upwelling of the isopycnal surfaces. However, total 230Th and 232Th versus salinity plots illustrate departures from binary mixing and provides evidence for non-conservative behavior of both isotopes along the section. We propose a model for total 230Th and 232Th scavenging and mixing along isopycnal surfaces. We use this model to estimate particle settling speeds and isopycnal eddy diffusion coefficients along the BGH section. Data-model comparison suggests particle settling velocities in the range of 400–700 m/y and isopycnal eddy diffusivity of the order of 2000 m2/s.

KW - Atlantic

KW - Isopycnal mixing

KW - Marine particles

KW - Southern ocean

KW - Thorium isotopes

U2 - 10.1016/j.dsr.2019.05.002

DO - 10.1016/j.dsr.2019.05.002

M3 - Article

SN - 0967-0637

VL - 149

JO - Deep-Sea Research Part I: Oceanographic Research Papers

JF - Deep-Sea Research Part I: Oceanographic Research Papers

M1 - 103042

ER -

Thorium isotopes in the Southeast Atlantic Ocean: Tracking scavenging during water mass mixing along neutral density surfaces

Abstract

Keywords

UN SDGs

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