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Abstract

Longwave radiation and turbulent heat
uxes are the mechanisms by which
the Earth's surface transfers heat into the atmosphere, thus aecting the surface
temperature. However, the energy partitioning between the radiative and
turbulent components is poorly constrained by energy and mass balances alone.
We use a simple energy balance model with the thermodynamic limit of maximum
power as an additional constraint to determine this partitioning. Despite
discrepancies over tropical oceans, we nd that the broad variation of
heat
uxes and surface temperatures in the ERA-Interim reanalysed observations
can be recovered from this approach. The estimates depend considerably
on the formulation of longwave radiative transfer and a spatially uniform
oset is related to the assumed cold temperature sink at which the heat
engine operates. Our results suggest that the steady state surface energy partitioning
may reect the maximum power constraint Turbulent heat
uxes are treated as the result of a heat engine operating
between the surface and the atmosphere.
Turbulent heat
uxes are determined by maximizing the mechanical power
output as an additional thermodynamic constraint.
Despite discrepancies over tropical ocean, broad patterns of turbulent fluxes and temperatures of ERA-Interim can be recovered.