@article{dc5db9f608934c57b5d6502f4b54ad6a,
title = "The North Atlantic Ocean Is in a State of Reduced Overturning",
abstract = "The Atlantic Meridional Overturning Circulation (AMOC) is responsible for a variable and climatically important northward transport of heat. Using data from an array of instruments that span the Atlantic at 26°N, we show that the AMOC has been in a state of reduced overturning since 2008 as compared to 2004–2008. This change of AMOC state is concurrent with other changes in the North Atlantic such as a northward shift and broadening of the Gulf Stream and altered patterns of heat content and sea surface temperature. These changes resemble the response to a declining AMOC predicted by coupled climate models. Concurrent changes in air-sea fluxes close to the western boundary reveal that the changes in ocean heat transport and sea surface temperature have altered the pattern of ocean-atmosphere heat exchange over the North Atlantic. These results provide strong observational evidence that the AMOC is a major factor in decadal-scale variability of North Atlantic climate.",
keywords = "AMOC, Atlantic, circulation, overturning",
author = "Smeed, {D. A.} and Josey, {S. A.} and C. Beaulieu and Johns, {W. E.} and Moat, {B. I.} and E. Frajka-Williams and D. Rayner and Meinen, {C. S.} and Baringer, {M. O.} and Bryden, {H. L.} and McCarthy, {G. D.}",
note = "Funding Information: This research was supported by grants from the UK Natural Environment Research Council for the RAPID-AMOC program and the ACSIS program (NE/ N018044/1), by the U.S. National Science Foundation (grant 1332978), by the U.S. National Oceanic and Atmospheric Administration (NOAA) Climate Program Office (fundRef 100007298), and by the U.S. NOAA Atlantic Oceanographic and Meteorological Laboratory. The authors thank the many officers, crews, and technicians who helped to collect these data. The RAPID-MOCHA-WBTS time series is available at http://www.rapid. ac.uk/rapidmoc. Other data sets used are as follows. Sea surface temperature: monthly mean values of the HadSST data from the UK Met Office Hadley Centre were downloaded from http:// www.metoffice.gov.uk/hadobs/hadisst/. Sea surface height: Aviso global gridded level 4 product was obtained from http://marine.copernicus.eu/. Subsurface temperature and salinity data: monthly mean values of the UK Met. Office EN4 data sets version 4.1.1/ 4.2.0 were obtained from http://www. metoffice.gov.uk/hadobs/en4/. Air-sea heat fluxes: monthly diagnostic surface data from the NOAA NCEP-NCAR CDAS-1 reanalysis project were obtained from http://iridl.ldeo.columbia.edu/. The anonymous reviewers provided many helpful suggestions for improving an earlier version of the manuscript. Publisher Copyright: {\textcopyright}2018. The Authors.",
year = "2018",
month = feb,
day = "16",
doi = "10.1002/2017GL076350",
language = "English (US)",
volume = "45",
pages = "1527--1533",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "American Geophysical Union",
number = "3",
}