Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012
The Atlantic Meridional Overturning Circulation (AMOC) has been observed continuously at 26° N since April 2004. The AMOC and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable based measurements of the Gulf Stream and satellite derived Ek...
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ftzenodo:oai:zenodo.org:29223 2024-09-15T18:20:41+00:00 Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012 D. A. Smeed G. McCarthy S. A. Cunningham E. Frajka-Williams D. Rayner W. E. Johns C. S. Meinen M. O. Baringer B. I. Moat A. Duchez H. L. Bryden 2013-09-13 https://doi.org/10.5194/osd-10-1619-2013 unknown Zenodo https://zenodo.org/communities/naclim https://zenodo.org/communities/eu https://doi.org/10.5194/osd-10-1619-2013 oai:zenodo.org:29223 info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode info:eu-repo/semantics/article 2013 ftzenodo https://doi.org/10.5194/osd-10-1619-2013 2024-07-26T23:28:13Z The Atlantic Meridional Overturning Circulation (AMOC) has been observed continuously at 26° N since April 2004. The AMOC and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable based measurements of the Gulf Stream and satellite derived Ekman transport. The time series has recently been extended to October 2012 and the results show a downward trend since 2004. From April~2008 to March 2012 the AMOC was an average of 2.7 Sv weaker than in the first four years of observation (95% confidence that the reduction is 0.3 Sv or more). Ekman transport reduced by about 0.2 Sv and the Gulf Stream by 0.5 Sv but most of the change (2.0 Sv) is due to the mid-ocean geostrophic flow. The change of the mid-ocean geostrophic flow represents a strengthening of the subtropical gyre above the thermocline. The increased southward flow of warm waters is balanced by a decrease in the southward flow of Lower North Atlantic Deep Water below 3000 m. The transport of Lower North Atlantic Deep Water slowed by 7% per year (95% confidence that the rate of slowing is greater than 2.5% per year). Article in Journal/Newspaper North Atlantic Deep Water North Atlantic Zenodo |
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The Atlantic Meridional Overturning Circulation (AMOC) has been observed continuously at 26° N since April 2004. The AMOC and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable based measurements of the Gulf Stream and satellite derived Ekman transport. The time series has recently been extended to October 2012 and the results show a downward trend since 2004. From April~2008 to March 2012 the AMOC was an average of 2.7 Sv weaker than in the first four years of observation (95% confidence that the reduction is 0.3 Sv or more). Ekman transport reduced by about 0.2 Sv and the Gulf Stream by 0.5 Sv but most of the change (2.0 Sv) is due to the mid-ocean geostrophic flow. The change of the mid-ocean geostrophic flow represents a strengthening of the subtropical gyre above the thermocline. The increased southward flow of warm waters is balanced by a decrease in the southward flow of Lower North Atlantic Deep Water below 3000 m. The transport of Lower North Atlantic Deep Water slowed by 7% per year (95% confidence that the rate of slowing is greater than 2.5% per year). |
format |
Article in Journal/Newspaper |
author |
D. A. Smeed G. McCarthy S. A. Cunningham E. Frajka-Williams D. Rayner W. E. Johns C. S. Meinen M. O. Baringer B. I. Moat A. Duchez H. L. Bryden |
spellingShingle |
D. A. Smeed G. McCarthy S. A. Cunningham E. Frajka-Williams D. Rayner W. E. Johns C. S. Meinen M. O. Baringer B. I. Moat A. Duchez H. L. Bryden Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012 |
author_facet |
D. A. Smeed G. McCarthy S. A. Cunningham E. Frajka-Williams D. Rayner W. E. Johns C. S. Meinen M. O. Baringer B. I. Moat A. Duchez H. L. Bryden |
author_sort |
D. A. Smeed |
title |
Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012 |
title_short |
Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012 |
title_full |
Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012 |
title_fullStr |
Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012 |
title_full_unstemmed |
Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012 |
title_sort |
observed decline of the atlantic meridional overturning circulation 2004 to 2012 |
publisher |
Zenodo |
publishDate |
2013 |
url |
https://doi.org/10.5194/osd-10-1619-2013 |
genre |
North Atlantic Deep Water North Atlantic |
genre_facet |
North Atlantic Deep Water North Atlantic |
op_relation |
https://zenodo.org/communities/naclim https://zenodo.org/communities/eu https://doi.org/10.5194/osd-10-1619-2013 oai:zenodo.org:29223 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode |
op_doi |
https://doi.org/10.5194/osd-10-1619-2013 |
_version_ |
1810459079307427840 |