Subpolar North Atlantic western boundary density anomalies and the Meridional Overturning Circulation

• Published in: Nature Communications
• Main Authors: Li, Feili, Lozier, M. Susan, Bacon, Sheldon, Bower, Amy S., Cunningham, Stuart A., de Jong, Marieke F., deYoung, Brad, Fraser, Neil, Fried, Nora, Han, Guoqi, Holliday, Naomi Penny, Holte, James W., Houpert, Loïc, Inall, Mark E., Johns, William E., Jones, Sam, Johnson, Clare, Karstensen, Johannes, Le Bras, Isabela A., Lherminier, Pascale, Lin, Xiaopei, Mercier, Herlé, Oltmanns, Marilena, Pacini, Astrid, Petit, Tillys, Pickart, Robert S., Rayner, Darren, Straneo, Fiamma, Thierry, Virginie, Visbeck, Martin, Yashayaev, Igor, Zhou, Chun
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Nature Research 2021
• Subjects: Bower; Holte; Rayner; North Atlantic
• Online Access: https://hdl.handle.net/1912/27451

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Li, F., Lozier, M. S., Bacon, S., Bower, A. S., Cunningham, S. A., de Jong, M. F., DeYoung, B., Fraser, N., Fried, N., Han, G., Holliday, N. P., Holte, J., Houpert, L., Inall, M. E., Johns, W. E., Jones, S., Johnson, C., Karstensen, J., Le Bras, I. A., P. Lherminier, X. Lin, H. Mercier, M. Oltmanns, A. Pacini, T. Petit, R. S. Pickart, D. Rayner, F. Straneo, V. Thierry, M. Visbeck, I. Yashayaev & Zhou, C. Subpolar North Atlantic western boundary density anomalies and the Meridional Overturning Circulation. Nature Communications, 12(1), (2021): 3002, https://doi.org/10.1038/s41467-021-23350-2. Changes in the Atlantic Meridional Overturning Circulation, which have the potential to drive societally-important climate impacts, have traditionally been linked to the strength of deep water formation in the subpolar North Atlantic. Yet there is neither clear observational evidence nor agreement among models about how changes in deep water formation influence overturning. Here, we use data from a trans-basin mooring array (OSNAP—Overturning in the Subpolar North Atlantic Program) to show that winter convection during 2014–2018 in the interior basin had minimal impact on density changes in the deep western boundary currents in the subpolar basins. Contrary to previous modeling studies, we find no discernable relationship between western boundary changes and subpolar overturning variability over the observational time scales. Our results require a reconsideration of the notion of deep western boundary changes representing overturning characteristics, with implications for constraining the source of overturning variability within and downstream of the subpolar region. We acknowledge funding from the Physical Oceanography Program of the U.S. National Science Foundation (OCE-1259398, OCE-1756231, OCE-1948335); the U.K. Natural Environment Research Council (NERC) National ...