An Alternative Way to Parameterizing the Nonlocal Scale Sensible Heat Flux Using the Flux Imbalance and K‐Theory Approach

Abstract Accurately representing the surface sensible heat flux (SHF) in Earth System Models (ESMs) is of paramount importance and challenge. This study introduces an alternative surface‐layer SHF correction scheme by modeling nonlocal scale SHF through flux imbalance (FI) prediction models while employing the conventional gradient diffusion approach (K‐theory) for the local scale part. This approach is termed the FLux IMbalance and K‐theory (FLIMK). The FLIMK relies solely on atmospheric stability parameters () and the ratio of measurement height to the boundary layer height (). The FLIMK underwent testing using large eddy simulation (LES) under dry convective boundary layer conditions with a prescribed stripe‐like heterogeneous SHF at the land surface. Additionally, the FLIMK scheme was incorporated into a numerical weather prediction (NWP) model and tested in the single‐column mode with data from the Atmospheric Radiation Measurement test case. The results indicate that K‐theory underestimates the SHF by approximately 15% due to the effects of the nonlocal scale. In contrast, the FLIMK scheme effectively reduces this imbalance, decreasing it from 15% (16%) to 6% (6.7%) for LES (NWP). The findings suggest that the FLIMK scheme can potentially enhance the parameterization of SHF in ESMs.