The Impact of Oceanic Heat Transport on the Atmospheric Circulation: a Thermodynamic Perspective

TL;DR

This study explores how increased oceanic heat transport influences atmospheric circulation and thermodynamic properties, revealing a decrease in climate system efficiency and entropy production, and highlighting the interconnectedness of oceanic and atmospheric processes.

Contribution

It demonstrates the thermodynamic effects of oceanic heat transport changes on climate system efficiency, entropy, and energy cycles using an aqua-planet model, providing new insights into climate dynamics.

Findings

Increased oceanic heat transport raises surface temperatures and reduces equator-to-pole temperature differences.

The total atmospheric heat transport remains nearly unchanged despite increased oceanic transport.

Climate system efficiency and entropy production decline with stronger oceanic heat transport.

Abstract

The present study investigates how global thermodynamic properties of the climate system are affected by the changes in the intensity of the imposed oceanic heat transport in an atmospheric general circulation model in aqua-planet configuration. Increasing the poleward oceanic heat transport results in an overall increase in the surface temperature and a decrease in the equator-to-pole surface temperature difference as a result of the ice-albedo feedback. Following the classical ansatz by Stone, the atmospheric heat transport changes in such a way that the total poleward heat transport remains almost unchanged. We also find that the efficiency of the climate machine, the intensity of the Lorenz energy cycle and the material entropy production of the system decline with increased oceanic heat transport which suggests that the climate system becomes less efficient and turns into a state of reduced entropy production, as the enhanced oceanic transport performs a stronger large-scale mixing between geophysical fluids with different temperature, thus reducing the availability in the climate system and bringing it closer to a state of thermal equilibrium.