Geographic variation of surface energy partitioning in the climatic mean predicted from the maximum power limit

TL;DR

This study introduces a simple energy balance model constrained by the maximum convective power limit to predict geographic variations in surface energy partitioning, aligning well with reanalysis data.

Contribution

It demonstrates that a thermodynamic limit on convective power can effectively predict spatial variations in surface heat fluxes and temperatures.

Findings

Model predictions match ERA-Interim data over land and ocean.

Surface temperature and heat flux variations depend on radiative transfer formulation.

A uniform offset relates to the assumed cold temperature sink.

Abstract

Convective and radiative cooling are the two principle mechanisms by which the Earth's surface transfers heat into the atmosphere and that shape surface temperature. However, this partitioning is not sufficiently constrained by energy and mass balances alone. We use a simple energy balance model in which convective fluxes and surface temperatures are determined with the additional thermodynamic limit of maximum convective power. We then show that the broad geographic variation of heat fluxes and surface temperatures in the climatological mean compare very well with the ERA-Interim reanalysis over land and ocean. We also show that the estimates depend considerably on the formulation of longwave radiative transfer and that a spatially uniform offset is related to the assumed cold temperature sink at which the heat engine operates.