It is frequently observed in field experiments that the eddy-covariance heat fluxes are systematically underestimated compared to the available energy, a phenomenon known as the surface energy balance (SEB) closure problem. A large-eddy simulation (LES) study is presented that investigates the behavior of turbulent organized structures (TOS) and their impact on the SEB closure problem. LES experiments are conducted for the daytime atmospheric boundary layer heated over a flat surface with atmospheric stability parameters \(- z_{i} /L\) ranging from 8 to 130. Local imbalance is defined as the deviation of the ‘observed’ heat flux at a grid point from the regionally ‘representative’ heat flux; systematic imbalance is defined as the horizontally averaged local imbalance. A thorough analysis of the correlation between local imbalance and various local variables is conducted. Local imbalance exhibited the most significant correlation with the variance of potential temperature, implying its potential usefulness in parameterizing local imbalance. In characterizing the vertical variation of systematic imbalance, the spatial variances of mean vertical velocity and potential temperature play key roles. Results reveal that TOS induced a correlation between the mean vertical velocity and potential temperature in a horizontal space, resulting in systematic imbalance. The local imbalance is further contributed by the inhomogeneous distribution of the observed heat flux. Our results advance the understanding of the SEB closure problem and pave a possible way for the development of parameterization schemes.
