William E. Johns

TL;DR: The vigor of the Atlantic meridional overturning circulation (MOC) is thought to be vulnerable to global warming, but its short-term temporal variability is unknown so changes inferred from sparse observations on the decadal time scale of recent climate change are uncertain this article.

TL;DR: In this paper, the authors used the Rapid Climate Change-Meridional Overturning Circulation (MOC) and Heatflux Array (RAPID-MOCHA) observing system deployed along 26.5°N for the period from April 2004 to October 2007.

TL;DR: The Atlantic meridional overturning circulation (AMOC) has been observed continuously at 26 N since April 2004 as mentioned in this paper, and the results show a downward trend since 2004, with an average of 2.7 Sv (1 Sv = 10 6 m 3 s 1 ) weaker than in the first four years of observation (95 % confidence that the reduction is 0.3 Sv or more).

TL;DR: The RAPID monitoring array has been providing continuous estimates of the AMOC and associated heat transport at 26°N in the North Atlantic since 2004 as mentioned in this paper, and the accuracy of ten day (annual) transports is 1.5 Sv (0.9 Sv).

TL;DR: It is suggested that the conversion of warm, salty, shallow Atlantic waters into colder, fresher, deep waters that move southward in the Irminger and Iceland basins is largely responsible for overturning and its variability in the subpolar basin.