  Limited surface observations of turbulent heat fluxes result in incomplete
knowledge about the surface energy balance that drives the climate system.
Here, we developed a novel, purely physics-based analytical method grounded on
the thermodynamic principle of maximum power. The approach derives the
turbulent heat flux only from the four inputs of incoming and outgoing
radiations at the land surface. The proposed approach does not use any
parameterization, unlike the existing surface energy balance models, and hence
does not suffer from uncertainty due to the same. We validated our methodology
with 102 eddy covariance observation stations around the globe with different
land use land covers. Using the satellite observations from CERES at a spatial
resolution of 1 degree, we have obtained spatially distributed global
analytical estimates of Sensible (H), latent heat (LE), and land surface heat
storage (delQs) fluxes for the first time. For a global observed land Net
radiation of 84 W/m2 from the satellite, we found H, LE and delQs to be 42
W/m2, 40 W/m2 and 2 W/m2, respectively. The theoretical and precise estimates
of all surface energy balance components will improve our understanding of
surface warming for different land use land covers across the globe.
