The ocean plays a critical role in the climate system by transferring heat from the tropics toward the poles, helping to regulate regional climates. How this heat transport may change in the future remains a first order question in climate science.

However, finding an answer to this question requires a through understanding of the processes that drive ocean heat transport in the current climate.

In this article we show that the ocean’s ability to move heat depends on diabatic processes, such as small-scale turbulence and surface forcing, that change the temperature of seawater parcels.

Annual average heat flux entering the ocean.
Annual average heat flux entering the ocean (colour, WM-2) and sea surface temperature contours (black lines) from global ocean model. The eastern tropical Pacific region dominates heat absorption by the ocean (indicated by red colours).

Diabatic processes in the tropical Pacific are found to play a particularly important role for the global ocean’s heat transport.

Our results highlight the need to represent these various processes well in climate models in order to accurately project future changes.