Global Estimates of Spatially Distributed Surface Energy Fluxes using Thermodynamic Principles

TL;DR

This paper introduces a physics-based analytical method to estimate surface energy fluxes globally using thermodynamic principles, validated with observations and satellite data, eliminating the need for parameterization.

Contribution

A novel, parameter-free analytical approach based on maximum power thermodynamics to estimate surface energy fluxes from radiative inputs.

Findings

Validated with 102 global observation stations.

Produced first spatially distributed global estimates of surface fluxes.

Estimated sensible, latent heat, and heat storage fluxes from satellite data.

Abstract

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.