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What causes the inverse relationship between primary production and export efficiency in the Southern Ocean?
journal contribution
posted on 2023-05-19, 04:22 authored by Le Moigne, FAC, Henson, SA, Emma Cavan, Georges, C, Pabortsava, K, Acterberg, EP, Ceballos-Romero, E, Zubkov, M, Sanders, RJThe ocean contributes to regulating atmospheric CO2 levels, partly via variability in the fraction of primary production (PP) which is exported out of the surface layer (i.e., the e ratio). Southern Ocean studies have found that contrary to global-scale analyses, an inverse relationship exists between e ratio and PP. This relationship remains unexplained, with potential hypotheses being (i) large export of dissolved organic carbon (DOC) in high PP areas, (ii) strong surface microbial recycling in high PP regions, and/or (iii) grazing-mediated export that varies inversely with PP. We find that the export of DOC has a limited influence in setting the negative e ratio/PP relationship. However, we observed that at sites with low PP and high e ratios, zooplankton-mediated export is large and surface microbial abundance low suggesting that both are important drivers of the magnitude of the e ratio in the Southern Ocean.
History
Publication title
Geophysical Research LettersVolume
43Issue
9Pagination
4457-4466ISSN
0094-8276Department/School
Institute for Marine and Antarctic StudiesPublisher
Amer Geophysical UnionPlace of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009Rights statement
2016 Crown copyright.Geophysical Research Letters Copyright 2016 American Geophysical Union. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/Repository Status
- Open