A Caltech Library Service

A nutrient relay sustains subtropical ocean productivity

Gupta, Mukund and Williams, Richard G. and Lauderdale, Jonathan M. and Jahn, Oliver and Hill, Christopher and Dutkiewicz, Stephanie and Follows, Michael J. (2022) A nutrient relay sustains subtropical ocean productivity. Proceedings of the National Academy of Sciences of the United States of America, 119 (41). Art. NO. e2206504119. ISSN 0027-8424. PMCID PMC9565266. doi:10.1073/pnas.2206504119.

[img] PDF - Published Version
Creative Commons Attribution.


Use this Persistent URL to link to this item:


The expansive gyres of the subtropical ocean account for a significant fraction of global organic carbon export from the upper ocean. In the gyre interior, vertical mixing and the heaving of nutrient-rich waters into the euphotic layer sustain local productivity, in turn depleting the layers below. However, the nutrient pathways by which these subeuphotic layers are themselves replenished remain unclear. Using a global, eddy-permitting simulation of ocean physics and biogeochemistry, we quantify nutrient resupply mechanisms along and across density surfaces, including the contribution of eddy-scale motions that are challenging to observe. We find that mesoscale eddies (10 to 100 km) flux nutrients from the shallow flanks of the gyre into the recirculating interior, through time-varying motions along density surfaces. The subeuphotic layers are ultimately replenished in approximately equal contributions by this mesoscale eddy transport and the remineralization of sinking particles. The mesoscale eddy resupply is most important in the lower thermocline for the whole subtropical region but is dominant at all depths within the gyre interior. Subtropical gyre productivity may therefore be sustained by a nutrient relay, where the lateral transport resupplies nutrients to the thermocline and allows vertical exchanges to maintain surface biological production and carbon export.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Gupta, Mukund0000-0003-0181-9504
Williams, Richard G.0000-0002-3180-7558
Lauderdale, Jonathan M.0000-0002-2993-7484
Jahn, Oliver0000-0002-0130-5186
Hill, Christopher0000-0003-3417-9056
Dutkiewicz, Stephanie0000-0002-0380-9679
Follows, Michael J.0000-0002-3102-0341
Additional Information:© 2022 the Author(s). Published by PNAS. This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY). M.G., J.M.L., O.J., C.H., S.D., and M.J.F. are grateful for support from the Simons Collaboration on Computational Biogeochemical Modeling of Marine Ecosystems (Simons Foundation grant 549931) and the Simons Collaboration on Ocean Processes and Ecology (Simons Foundation grant 721248). R.G.W. is grateful for support from the UK Natural Environment Research Council (grant NE/T007788/1). C.H. and S.D. additionally acknowledge support from NASA (grant 80NSSC22K0153). We also appreciate insightful comments from two reviewers, who helped improve the manuscript. Data, Materials, and Software Availability. The setup files used to generate the numerical simulation are available at (53), the Darwin model output is provided at (54), the satellite-based primary production estimates are available at (62), and the isopycnal decomposition tool is posted at (60).
Funding AgencyGrant Number
Simons Foundation549931
Natural Environment Research Council (NERC)T007788
Issue or Number:41
PubMed Central ID:PMC9565266
Record Number:CaltechAUTHORS:20230206-9037800.6
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:119054
Deposited By: Research Services Depository
Deposited On:09 Mar 2023 17:37
Last Modified:09 Mar 2023 17:37

Repository Staff Only: item control page