@article{39c746e11bbc483f9705321699094433,
title = "Southern Ocean carbon sink enhanced by sea-ice feedbacks at the Antarctic Cold Reversal",
abstract = "The Southern Ocean occupies 14% of the Earth{\textquoteright}s surface and plays a fundamental role in the global carbon cycle and climate. It provides a direct connection to the deep ocean carbon reservoir through biogeochemical processes that include surface primary productivity, remineralization at depth and the upwelling of carbon-rich water masses. However, the role of these different processes in modulating past and future air–sea carbon flux remains poorly understood. A key period in this regard is the Antarctic Cold Reversal (ACR, 14.6–12.7 kyr bp), when mid- to high-latitude Southern Hemisphere cooling coincided with a sustained plateau in the global deglacial increase in atmospheric CO2. Here we reconstruct high-latitude Southern Ocean surface productivity from marine-derived aerosols captured in a highly resolved horizontal ice core. Our multiproxy reconstruction reveals a sustained signal of enhanced marine productivity across the ACR. Transient climate modelling indicates this period coincided with maximum seasonal variability in sea-ice extent, implying that sea-ice biological feedbacks enhanced CO2 sequestration and created a substantial regional marine carbon sink, which contributed to the plateau in CO2 during the ACR. Our results highlight the role Antarctic sea ice plays in controlling global CO2, and demonstrate the need to incorporate such feedbacks into climate–carbon models.",
author = "Fogwill, {C. J.} and Turney, {C. S.M.} and L. Menviel and A. Baker and Weber, {M. E.} and B. Ellis and Thomas, {Z. A.} and Golledge, {N. R.} and D. Etheridge and M. Rubino and Thornton, {D. P.} and {van Ommen}, {T. D.} and Moy, {A. D.} and Curran, {M. A.J.} and S. Davies and Bird, {M. I.} and Munksgaard, {N. C.} and Rootes, {C. M.} and H. Millman and J. Vohra and A. Rivera and A. Mackintosh and J. Pike and Hall, {I. R.} and Bagshaw, {E. A.} and E. Rainsley and C. Bronk-Ramsey and M. Montenari and Cage, {A. G.} and Harris, {M. R.P.} and R. Jones and A. Power and J. Love and J. Young and Weyrich, {L. S.} and A. Cooper",
note = "Funding Information: C.J.F., C.S.M.T., L.M., N.R.G., L.S.W. and A.C. are supported by their respective Australian Research Council (ARC) and Royal Society of NZ fellowships, and C.J.F. and A.G.C. thank Keele University for a Research Development Award that underpinned this research at Keele University IceLab and Exeter University. Fieldwork was undertaken under ARC Linkage Project (LP120200724), supported by Linkage Partner Antarctic Logistics and Expeditions, whose enduring support we acknowledge. CSIRO{\textquoteright}s contribution was supported in part by the Australian Climate Change Science Program (ACCSP), an Australian Government Initiative. S.D. acknowledges financial support from Coleg Cymraeg Cenedlaethol and the European Research Council (ERC grant agreement no. 25923). M.E.W. acknowledges support from the Deutsche Forschungsgemeinschaft (grant no. We2039/8-1). Finally, we thank H. Glanville for comments on the final draft of the manuscript, and A. Jeffery for advice on SEM analysis. Publisher Copyright: {\textcopyright} 2020, The Author(s), under exclusive licence to Springer Nature Limited.",
year = "2020",
month = jul,
day = "1",
doi = "10.1038/s41561-020-0587-0",
language = "English (US)",
volume = "13",
pages = "489--497",
journal = "Nature Geoscience",
issn = "1752-0894",
publisher = "Nature Publishing Group",
number = "7",
}