On the Causal Relationship between Poleward Heat Flux and the Equator-to-Pole Temperature Gradient: A Cautionary Tale

Abstract

An increase in the poleward heat or energy transport is often ascribed to a strengthening of the equator-to-pole gradient in temperature or in the top-of-the-atmosphere (TOA) net radiation. While this attribution conforms to the well-established flux gradient relationship, a counterexample is shown here, demonstrating that a forced atmospheric circulation, triggered by enhanced convection over the western tropical Pacific warm pool and suppressed convection over the eastern tropical Pacific and Indian Oceans, can cause the equator-to-pole gradient in the TOA net radiation to increase.