Technical Note: A note on stabilization mechanisms of, e.g., Atlantic Ocean meridional overturning circulation

The extent of anthropogenic influence on the Earth’s climate warrants studies of the ocean as a major player. The ocean circulation is important for transporting properties like heat, carbon and nutrients. A supposed major conduit is the Atlantic Meridional Overturning Circulation (AMOC). As the AMOC is a complex nonlinear dynamical system, it is challenging to predict its potential to collapse and/or reversal of direction from a statistical viewpoint using a single parameter like sea-surface temperature or freshwater influx in numerical models. However, as is argued in this note supported by spectra from ocean observations, physical processes such as transport by sub-mesoscale eddies and turbulence-generating breaking of internal waves that are not incorporated in these models will alter such parameters, and thereby statistical analyses. This may lead to feed-back mechanisms on property gradients such as density stratification so that the AMOC may not collapse.