CaltechAUTHORS
Published December 2024 | Published
Journal Article Open

Interactions Between Multiple Physical Particle Injection Pumps in the Southern Ocean

Thompson, Andrew F.1 ORCID icon
Dove, Lilian A.1, 2 ORCID icon
Flint, Ellie1, 3
Lacour, Leo4, 5 ORCID icon
Boyd, Philip4 ORCID icon
  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Brown University
  • 3. ROR icon University of California, San Diego
  • 4. ROR icon University of Tasmania
  • 5. ROR icon Villefranche Oceanographic Laboratory

Abstract

Contributions to the biological pump that arise from the physical circulation are referred to as physical particle injection pumps. A synthesized view of how these physical pumps interact with each other and other components of the biological pump does not yet exist. Here, observations from a quasi-Lagrangian float and an ocean glider, deployed in the Southern Ocean's Subantarctic Zone for one month during the spring bloom, offer insight into daily-to-monthly fluctuations in the mixed layer pump (MLP) and the eddy subduction pump (ESP). Estimated independently, each mechanism contributes intermittent export fluxes of roughly several hundred milligrams of particulate organic carbon (POC) per square meter per day. The glider-based estimates indicate sustained weekly periods of MLP export fluxes across the base of the mixed layer with a magnitude of ∼450±110 mg POC m−2 day−1. Potential export fluxes from the ESP, based on a mixed layer instability scaling, occasionally exceed 400 mg POC m−2 day−1, with export elevated due to both strong inferred vertical velocities and enhanced isopycnal slopes. Significant export fluxes from the ESP are localized to the edges of mesoscale eddies and to fronts, whereas the MLP acts more broadly due to the larger scales of atmospheric forcing. Regimes occur when MLP and ESP export fluxes can have either the same or opposite sign. Simple summation of fluxes from existing parameterizations of the two pumps likely misrepresents the total physical carbon flux. Insights into how mesoscale stirring and submesoscale velocities set POC vertical structure is a key target to reduce uncertainty in global carbon export fluxes.

Copyright and License

© 2024 The Author(s). This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Acknowledgement

We are grateful for the efforts of the full SOLACE field team as well as the captain and crew of the R/V Investigator. We extend particular thanks to Tyler Rohr who took on extra glider testing, deployment and troubleshooting responsibilities during the cruise due to COVID travel restrictions. The authors acknowledge helpful suggestions and conversations from Elizabeth, Shadwick, Tom Trull, Mara Freilich, and Alice Della Penna. AFT, LAD and EF were supported by the Resnick Sustainability Institute and the Ginkgo Foundation; LAD received additional support from an NSF Graduate Research Fellowship and a NOAA Climate & Global Change Postdoctoral Fellowship. EF's contributions were supported by a Summer Undergraduate Research Fellowship at Caltech. LL was supported by a European Union's Horizon 2020 Marie Sklodowska-Curie Grant (no. 892653). PWB was funded by the Australian Research Council by Laureate Fellowship FL160100131. This research was supported by a grant of sea time on RV Investigator from the CSIRO Marine National Facility (https://ror.org/01mae9353).

Supplemental Material

Supporting Information S1: 2024GB008122-sup-0001-Supporting Information SI-S01.pdf

Data Availability

Surface flux and forcing data is available through the Australian Ocean Data Network (IMOS, 2022) at https://imos.org.au/facility/deep-water-moorings/southern-ocean-time-series-observatory. Sea level anomaly and surface velocity products were produced and distributed by the Copernicus Marine 360 and Environment Monitoring Service (Copernicus Climate Change Service, 2018) and are available at https://data.marine.copernicus.eu/product/SEALEVEL_GLO_PHY_L4_MY_008_047/description. Finite-size Lyapunov Exponents were produced and distributed by AVISO+ (AVISO, 2022) and are available at https://www.aviso.altimetry.fr/en/data/products/value-added-products/fsle-finite-size-lyapunov-exponents.html.

Glider data presented in this work has been uploaded to the NOAA National Centers for Environmental Information (NCEI) database (Thompson & Dove 2023) and is accessible at https://www.ncei.noaa.gov/archive/accession/0276999. Float data can be downloaded from the Argo Global Data Assembly Center (Argo, 2000) (ftp://ftp.ifremer.fr/ifremer/argo/). These data were collected and made freely available by the International Argo Program and the national programs that contribute to it (http://www.argo.ucsd.edu, https://www.ocean-ops.org). The Argo Program is part of the Global Ocean Observing System.

Files

Global Biogeochemical Cycles - 2024 - Thompson - Interactions Between Multiple Physical Particle Injection Pumps in the.pdf

Additional details

Funding Dates Caltech Custom Metadata
Created:
March 4, 2025
Modified:
March 4, 2025