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The biogeochemical structure of Southern Ocean mesoscale eddies

Citation

Patel, RS and Llort, J and Strutton, PG and Phillips, HE and Moreau, S and Conde Pardo, P and Lenton, A, The biogeochemical structure of Southern Ocean mesoscale eddies, Journal of Geophysical Research: Oceans, 125, (8) Article e2020JC016115. ISSN 2169-9275 (2020) [Refereed Article]


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Copyright Statement

Copyright 2020 American Geophysical Union.

DOI: doi:10.1029/2020JC016115

Abstract

Mesoscale eddies play a key role in modulating physical and biogeochemical properties across the global ocean. They also play a central role in cross‐frontal transport of heat, freshwater, and carbon, especially in the Southern Ocean. However, the role that eddies play in the biogeochemical cycles is not yet well constrained, partly due to a lack of observations below the surface. Here, we use hydrographic data from two voyages, conducted in the austral summer and autumn, to document the vertical biogeochemical structure of two mesoscale cyclonic eddies and quantify the role of these eddies in the meridional transport of nutrients across the Subantarctic Front. Our study demonstrates that the nutrient distribution is largely driven by eddy dynamics, yielding identical eddy structure below the mixed layer in both seasons. This result allowed us to relate nutrient content to dynamic height and estimate the average transport by eddies across the Subantarctic Front. We found that relative to Subantarctic Zone waters, long‐lived cold‐core eddies carry nitrate anomalies of 1.60.21010 moles and silicate anomalies of −5.50.71010 moles across the fronts each year. This cross‐frontal transport of nutrients has negligible impact on Subantarctic Zone productivity; however, it has potential to modify the nutrient content of mode waters that are exported from the Southern Ocean to lower latitudes.

Item Details

Item Type:Refereed Article
Keywords:Southern Ocean, eddies, nutrient transport, biomass, stoichiometry, observations
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical oceanography
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Understanding climate change
Objective Field:Climate variability (excl. social impacts)
UTAS Author:Patel, RS (Mr Ramkrushnbhai Patel)
UTAS Author:Llort, J (Dr Joan Llort Jordi)
UTAS Author:Strutton, PG (Professor Peter Strutton)
UTAS Author:Phillips, HE (Associate Professor Helen Phillips)
UTAS Author:Moreau, S (Dr Sebastien Moreau)
UTAS Author:Conde Pardo, P (Dr Paula Conde Pardo)
UTAS Author:Lenton, A (Dr Andrew Lenton)
ID Code:140595
Year Published:2020
Funding Support:Australian Research Council (DP160102870)
Web of Science® Times Cited:3
Deposited By:Oceans and Cryosphere
Deposited On:2020-08-29
Last Modified:2021-02-11
Downloads:2 View Download Statistics

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