TY - GEN
T1 - Rapid coastal deoxygenation due to ocean circulation shift in the northwest Atlantic
AU - Claret, Mariona
AU - Galbraith, Eric D.
AU - Palter, Jaime B.
AU - Bianchi, Daniele
AU - Fennel, Katja
AU - Gilbert, Denis
AU - Dunne, John P.
N1 - Publisher Copyright:
© 2018, The Author(s).
PY - 2018/10/1
Y1 - 2018/10/1
N2 - Global observations show that the ocean lost approximately 2% of its oxygen inventory over the past five decades1–3, with important implications for marine ecosystems4,5. The rate of change varies regionally, with northwest Atlantic coastal waters showing a long-term drop6,7 that vastly outpaces the global and North Atlantic basin mean deoxygenation rates5,8. However, past work has been unable to differentiate the role of large-scale climate forcing from that of local processes. Here, we use hydrographic evidence to show that a Labrador Current retreat is playing a key role in the deoxygenation on the northwest Atlantic shelf. A high-resolution global coupled climate–biogeochemistry model9 reproduces the observed decline of saturation oxygen concentrations in the region, driven by a retreat of the equatorward-flowing Labrador Current and an associated shift towards more oxygen-poor subtropical waters on the shelf. The dynamical changes underlying the shift in shelf water properties are correlated with a slowdown in the simulated Atlantic Meridional Overturning Circulation (AMOC)10. Our results provide strong evidence that a major, centennial-scale change of the Labrador Current is underway, and highlight the potential for ocean dynamics to impact coastal deoxygenation over the coming century.
AB - Global observations show that the ocean lost approximately 2% of its oxygen inventory over the past five decades1–3, with important implications for marine ecosystems4,5. The rate of change varies regionally, with northwest Atlantic coastal waters showing a long-term drop6,7 that vastly outpaces the global and North Atlantic basin mean deoxygenation rates5,8. However, past work has been unable to differentiate the role of large-scale climate forcing from that of local processes. Here, we use hydrographic evidence to show that a Labrador Current retreat is playing a key role in the deoxygenation on the northwest Atlantic shelf. A high-resolution global coupled climate–biogeochemistry model9 reproduces the observed decline of saturation oxygen concentrations in the region, driven by a retreat of the equatorward-flowing Labrador Current and an associated shift towards more oxygen-poor subtropical waters on the shelf. The dynamical changes underlying the shift in shelf water properties are correlated with a slowdown in the simulated Atlantic Meridional Overturning Circulation (AMOC)10. Our results provide strong evidence that a major, centennial-scale change of the Labrador Current is underway, and highlight the potential for ocean dynamics to impact coastal deoxygenation over the coming century.
UR - http://www.scopus.com/inward/record.url?scp=85053659488&partnerID=8YFLogxK
U2 - 10.1038/s41558-018-0263-1
DO - 10.1038/s41558-018-0263-1
M3 - Other contribution
AN - SCOPUS:85053659488
VL - 8
T3 - Nature Climate Change
ER -