  The North Atlantic Ocean circulation, fueled by winds and surface buoyancy
fluxes, carries 1.25$\,$PettaWatts of heat poleward in the subtropics, and
plays an important role in regulating global weather and climate patterns.
Using a series of simulations with perturbed surface forcing, we study how
winds and surface heat flux gradients affect the Atlantic meridional heat
transport. We decompose the Atlantic meridional heat transport into
contributions from circulation cells at warm and cold temperatures (resembling
a subtropical gyre and the dense overturning circulation respectively), and a
mixed circulation that contains water masses traversing both these cells.
Variations in wind stress initially alter the amount of heat carried by the
warm and mixed cells, but on long time scales ($>$10 years), changes in the
temperature distribution restore the heat transport to equilibrium. Changes in
surface buoyancy forcing control the cold cell's circulation, and its
associated meridional heat transport, through high-latitude processes.
