Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean
Iron is an essential micronutrient for life. However, its scarcity limits algae growth in about one-half of the ocean. Its cycle is therefore linked to the global carbon cycle and climate. We present an iron isotope section from the Southern Ocean. In contrast to the common but oversimplified view,...
Published in: | Proceedings of the National Academy of Sciences |
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Main Authors: | , , , , |
Format: | Text |
Language: | English |
Published: |
National Academy of Sciences
2017
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Subjects: | |
Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5293069/ http://www.ncbi.nlm.nih.gov/pubmed/28096366 https://doi.org/10.1073/pnas.1603107114 |
Summary: | Iron is an essential micronutrient for life. However, its scarcity limits algae growth in about one-half of the ocean. Its cycle is therefore linked to the global carbon cycle and climate. We present an iron isotope section from the Southern Ocean. In contrast to the common but oversimplified view, according to which organic matter remineralization is the major pathway releasing dissolved iron below the surface layers, these data reveal other dominant processes at depth, likely abiotic desorption/dissolution from lithogenic particles. This suggests that the iron cycle, and therefore primary production and climate, may be more sensitive than previously thought to continental erosion, dissolved/particle interactions, and deep water upwelling. These processes likely impact other elements in the ocean. |
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