An Evaluation of Algebraic Turbulence Length Scale Formulations

Turbulence kinetic energy (TKE) schemes are routinely used for turbulence parameterization in numerical weather prediction models. A key component of these is the so-called length scale. Novel scale-aware, budget-based diagnostics that account cross-scale transfer variances to evaluate performance selected scale formulations gray zone turbulence. The computed using coarse-graining method on high resolution large eddy simulation data idealized cases. vertical profiles and temporal evolution scales analyzed. Additionally, local normalized root mean square error a non-local three-component technique tailored specifically evaluation. Based our analyses, we recommend length-scale depend not only boundary layer height, but also TKE stratification. Such able perform satisfactorily different flow regimes, their scale-awareness still limited. Only Honnert et al. formulation shows stronger thanks its cut-off relationship zone. However, contrast diagnostics, dependence does change with height.