Abstract
The debate over the historical and future evolution of the Atlantic
Meridional Overturning Circulation (AMOC) has united scientists around a
single topic, but this community has yet to unite around a single
definition of the AMOC. In an effort to focus the debate around dynamics
rather than semantics, we recommend that the community universally adopt
a definition of the AMOC in density coordinates. We present evidence
that the traditional depth space definition is insufficient at capturing
elements of this circulation, especially at high latitudes where the
northward and southward limbs of the AMOC are separated horizontally
rather than vertically. Instead, the AMOC in density coordinates more
realistically captures the water mass transformation process at high
latitudes, shifts the maximum AMOC from the subtropical to the subpolar
North Atlantic where the majority of the deep waters are formed, and
depicts the peak in meridional heat transport associated with the
subtropical gyre.