A Model of the Energy Balance Gap Based on Atmospheric Stability and Surface Heterogeneity

Secondary circulations are one of the main causes of the energy balance gap that arises from the underestimation of sensible and latent heat fluxes by eddy covariance measurements because they cannot capture the energy transported by the mean wind, i.e. the so-called dispersive flux. The magnitude of the missed sensible and latent dispersive fluxes depends significantly on atmospheric stability and surface thermal heterogeneity, but there is currently no correction method that accounts for both of these relationships. Using an idealized large-eddy simulation study, we have further developed an existing approach that models the energy balance gap as a function of atmospheric stability by additionally including thermal surface heterogeneity in the parametrization. This new model has already been tested on eddy covariance measurements that were carried out at 17 stations over the course of three months during the CHEESEHEAD19 (Chequamegon Heterogeneous Ecosystem Energy-balance Study Enabled by a High-density Extensive Array of Detectors) measurement campaign and it provides promising results.