A sea change in our view of overturning in the subpolar North Atlantic

To provide an observational basis for the Intergovernmental Panel on Climate Change projections of a slowing Atlantic meridional overturning circulation (MOC) in the 21st century, the Overturning in the Subpolar North Atlantic Program (OSNAP) observing system was launched in the summer of 2014. The first 21-month record reveals a highly variable overturning circulation responsible for the majority of the heat and freshwater transport across the OSNAP line. In a departure from the prevailing view that changes in deep water formation in the Labrador Sea dominate MOC variability, these results suggest that the conversion of warm, salty, shallow Atlantic waters into colder, fresher, deep waters that move southward…

• NS
  National Science Foundation

  Awards: NSF-OCE-12-59013, NSF-OCE-12-59102
• SR
  Sight Research UK

  Awards: NE/R015953/1, noc010012, NE/K010700/1, NE/N018001/1, NE/K010948/1, NE/K010875/1, NE/H01988X/1, NE/T00858X/2, NE/T00858X/1, NE/K010972/1
• NE
  Natural Environment Research Council

  Awards: NE/T00858X/1, NE/K010948/1, NE/H01988X/1, NE/T00858X/2, NE/R015953/1, NE/K010875/1, noc010012, NE/K010700/1, NE/K010972/1, NE/N018001/1