Type

Journal Article

Authors

V. Saba
G. Feulner
A. Robinson
Stefan Rahmstorf
Levke Caesar

Subjects

Geology

Topics
high resolution twentieth century atlantic ocean nineteenth century atmospheric carbon dioxide north atlantic carbon dioxide concentrations sea surface temperature

Observed fingerprint of a weakening Atlantic Ocean overturning circulation (2018)

Abstract The Atlantic meridional overturning circulation (AMOC)—a system of ocean currents in the North Atlantic—has a major impact on climate, yet its evolution during the industrial era is poorly known owing to a lack of direct current measurements. Here we provide evidence for a weakening of the AMOC by about 3±1 sverdrups (around 15 per cent) since the mid-twentieth century. This weakening is revealed by a characteristic spatial and seasonal sea-surface temperature ‘fingerprint’—consisting of a pattern of cooling in the subpolar Atlantic Ocean and warming in the Gulf Stream region— and is calibrated through an ensemble of model simulations from the CMIP5 project. We find this fingerprint both in a high-resolution climate model in response to increasing atmospheric carbon dioxide concentrations, and in the temperature trends observed since the late nineteenth century. The pattern can be explained by a slowdown in the AMOC and reduced northward heat transport, as well as an associated northward shift of the Gulf Stream. Comparisons with recent direct measurements from the RAPID project and several other studies provide a consistent depiction of recordlow AMOC values in recent years.
Collections Ireland -> Maynooth University -> Type = Article
Ireland -> Maynooth University -> Academic Unit = Faculty of Social Sciences: Research Institutes: Irish Climate Analysis and Research Units, ICARUS
Ireland -> Maynooth University -> Academic Unit = Faculty of Social Sciences: Geography
Ireland -> Maynooth University -> Status = Published

Full list of authors on original publication

V. Saba, G. Feulner, A. Robinson, Stefan Rahmstorf, Levke Caesar

Experts in our system

1
Stefan Rahmstorf
Maynooth University
Total Publications: 3