Stably stratified interfacial-layer turbulence from large-eddy simulation

The structure of the interfacial layer capping the atmospheric boundary lay er is not well understood. The dominant influence on turbulence within the interfacial layer is the stable stratification induced by the capping inver sion. A series of 26 high-resolution large eddy simulation runs ranging fro m neutral, inversion-capped to free-convection cases are used to study inte rfacial layer turbulence. The interfacial layer is found to be similar in m any aspects to a classic stable boundary layer. For example, the shapes of interfacial layer spectra and cospectra, including the locations of the spe ctral peaks, agree with previous observations from nocturnal PBLs. The eddy diffusivities, variances, structure-function parameters, and dissipation r ates within the interfacial layer, suitably nondimensionalized using local scaling, also agree with observations from nocturnal PBLs. These results ma y lead to improved models of the interfacial layer and entrainment, and may also have implications for remote sensing of the interfacial layer.