Stationary Rossby waves dominate subduction of anthropogenic carbon in the Southern Ocean
The Southern Ocean has taken up more than 40% of the total anthropogenic carbon (C ant ) stored in the oceans since the preindustrial era, mainly in subantarctic mode and intermediate waters (SAMW-AAIW). However, the physical mechanisms responsible for the transfer of C ant into the ocean interior r...
Published in: | Scientific Reports |
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Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Nature Publishing Group
2017
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Subjects: | |
Online Access: | https://doi.org/10.1038/s41598-017-17292-3 http://www.ncbi.nlm.nih.gov/pubmed/29213120 http://ecite.utas.edu.au/123642 |
Summary: | The Southern Ocean has taken up more than 40% of the total anthropogenic carbon (C ant ) stored in the oceans since the preindustrial era, mainly in subantarctic mode and intermediate waters (SAMW-AAIW). However, the physical mechanisms responsible for the transfer of C ant into the ocean interior remain poorly understood. Here, we use high resolution (1/10) ocean simulations to investigate these mechanisms at the SAMW-AAIW subduction hotspots. Mesoscale Stationary Rossby Waves (SRWs), generated where the Antarctic Circumpolar Current interacts with topography, make the dominant contribution to the C ant transfer in SAMW-AAIW in the Indian and Pacific sectors (66% and 95% respectively). Eddy-resolving simulations reproduce the observed C ant sequestration in these layers, while lower spatial resolution models, that do not reproduce SRWs, underestimate the inventory of C ant in these layers by 40% and overestimate the storage in denser layers. A key implication is that climate model simulations, that lack sufficient resolution to represent sequestration by SRWs, are therefore likely to overestimate the residence time of C ant in the ocean, with implications for simulated rates of climate change. |
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