Freshwater displacement effect on the Weddell Gyre carbon budget

Benjamin A. Taylor; Graeme A. MacGilchrist; Matthew R. Mazloff; Lynne D. Talley

doi:10.1029/2023GL103952

Freshwater displacement effect on the Weddell Gyre carbon budget

Benjamin A. Taylor^*, Graeme A. MacGilchrist, Matthew R. Mazloff, Lynne D. Talley

^*Corresponding author for this work

School of Earth & Environmental Sciences

Research output: Contribution to journal › Article › peer-review

Abstract

The Weddell Gyre mediates carbon exchange between the abyssal ocean and atmosphere, which is critical to global climate. This region also features large and highly variable freshwater fluxes due to seasonal sea ice, net precipitation, and glacial melt; however, the impact of these freshwater fluxes on the regional carbon cycle has not been fully appreciated. Using a novel budget analysis of dissolved inorganic carbon (DIC) mass in the Biogeochemical Southern Ocean State Estimate, we highlight two freshwater-driven transports. Where freshwater with minimal DIC enters the ocean, it displaces DIC-rich seawater outwards, driving a lateral transport of 75 ± 5 Tg DIC/year. Additionally, sea ice export requires a compensating import of seawater, which carries 48 ± 11 Tg DIC/year into the gyre. Though often overlooked, these freshwater displacement effects are of leading order in the Weddell Gyre carbon budget in the state estimate and in regrouped box-inversion estimates, with implications for evaluating basin-scale carbon transport.

Original language	English
Article number	e2023GL103952
Journal	Geophysical Research Letters
Volume	50
Issue number	18
DOIs	https://doi.org/10.1029/2023GL103952
Publication status	Published - 26 Sept 2023

Keywords

Carbon budget
Freshwater
Weddell
Oceanic carbon transport
Sea ice
Divergence

UN SDGs

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

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10.1029/2023GL103952Licence: CC BY

Taylor_2023_GRL_Freshwater-displacement_CC
Copyright © 2023. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Final published version, 3.13 MBLicence: CC BY

CO2 and climate change: CO2 and climate change: deciphering the role of the high-latitude oceans
MacGilchrist, G. (PI)
Medical Research Council
17/09/22 → 16/09/26
Project: Standard

Cite this

@article{8be37bd586d04955b2500d711cd5c374,

title = "Freshwater displacement effect on the Weddell Gyre carbon budget",

abstract = "The Weddell Gyre mediates carbon exchange between the abyssal ocean and atmosphere, which is critical to global climate. This region also features large and highly variable freshwater fluxes due to seasonal sea ice, net precipitation, and glacial melt; however, the impact of these freshwater fluxes on the regional carbon cycle has not been fully appreciated. Using a novel budget analysis of dissolved inorganic carbon (DIC) mass in the Biogeochemical Southern Ocean State Estimate, we highlight two freshwater-driven transports. Where freshwater with minimal DIC enters the ocean, it displaces DIC-rich seawater outwards, driving a lateral transport of 75 ± 5 Tg DIC/year. Additionally, sea ice export requires a compensating import of seawater, which carries 48 ± 11 Tg DIC/year into the gyre. Though often overlooked, these freshwater displacement effects are of leading order in the Weddell Gyre carbon budget in the state estimate and in regrouped box-inversion estimates, with implications for evaluating basin-scale carbon transport.",

keywords = "Carbon budget, Freshwater, Weddell, Oceanic carbon transport, Sea ice, Divergence",

author = "Taylor, {Benjamin A.} and MacGilchrist, {Graeme A.} and Mazloff, {Matthew R.} and Talley, {Lynne D.}",

note = "This work was funded by NSF's Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) Project under NSF awards PLR-1425989 and OPP-1936222. G.A.M was additionally supported under UKRI Grant MR/W013835/1. M.R.M. also acknowledges support from NASA grant 80NSSC20K1076 and NSF grants OCE-1924388 and OPP-2149501. ",

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language = "English",

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T1 - Freshwater displacement effect on the Weddell Gyre carbon budget

AU - Taylor, Benjamin A.

AU - MacGilchrist, Graeme A.

AU - Mazloff, Matthew R.

AU - Talley, Lynne D.

N1 - This work was funded by NSF's Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) Project under NSF awards PLR-1425989 and OPP-1936222. G.A.M was additionally supported under UKRI Grant MR/W013835/1. M.R.M. also acknowledges support from NASA grant 80NSSC20K1076 and NSF grants OCE-1924388 and OPP-2149501.

PY - 2023/9/26

Y1 - 2023/9/26

N2 - The Weddell Gyre mediates carbon exchange between the abyssal ocean and atmosphere, which is critical to global climate. This region also features large and highly variable freshwater fluxes due to seasonal sea ice, net precipitation, and glacial melt; however, the impact of these freshwater fluxes on the regional carbon cycle has not been fully appreciated. Using a novel budget analysis of dissolved inorganic carbon (DIC) mass in the Biogeochemical Southern Ocean State Estimate, we highlight two freshwater-driven transports. Where freshwater with minimal DIC enters the ocean, it displaces DIC-rich seawater outwards, driving a lateral transport of 75 ± 5 Tg DIC/year. Additionally, sea ice export requires a compensating import of seawater, which carries 48 ± 11 Tg DIC/year into the gyre. Though often overlooked, these freshwater displacement effects are of leading order in the Weddell Gyre carbon budget in the state estimate and in regrouped box-inversion estimates, with implications for evaluating basin-scale carbon transport.

AB - The Weddell Gyre mediates carbon exchange between the abyssal ocean and atmosphere, which is critical to global climate. This region also features large and highly variable freshwater fluxes due to seasonal sea ice, net precipitation, and glacial melt; however, the impact of these freshwater fluxes on the regional carbon cycle has not been fully appreciated. Using a novel budget analysis of dissolved inorganic carbon (DIC) mass in the Biogeochemical Southern Ocean State Estimate, we highlight two freshwater-driven transports. Where freshwater with minimal DIC enters the ocean, it displaces DIC-rich seawater outwards, driving a lateral transport of 75 ± 5 Tg DIC/year. Additionally, sea ice export requires a compensating import of seawater, which carries 48 ± 11 Tg DIC/year into the gyre. Though often overlooked, these freshwater displacement effects are of leading order in the Weddell Gyre carbon budget in the state estimate and in regrouped box-inversion estimates, with implications for evaluating basin-scale carbon transport.

KW - Carbon budget

KW - Freshwater

KW - Weddell

KW - Oceanic carbon transport

KW - Sea ice

KW - Divergence

U2 - 10.1029/2023GL103952

DO - 10.1029/2023GL103952

M3 - Article

SN - 0094-8276

VL - 50

JO - Geophysical Research Letters

JF - Geophysical Research Letters

IS - 18

M1 - e2023GL103952

ER -

Freshwater displacement effect on the Weddell Gyre carbon budget

Abstract

Keywords

UN SDGs

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Projects

CO2 and climate change: CO2 and climate change: deciphering the role of the high-latitude oceans

Cite this