One-dimensional turbulence model for dry atmospheric boundary layer flows

One-dimensional turbulence (ODT) offers an alternative single-column solver for wall-bounded turbulence that sits between traditional 1D boundary-layer parametrisations and fully 3D direct numerical simulation: in fully resolved mode, molecular transport is explicitly resolved along a 1D vertical domain, while turbulent advection is represented by instantaneous spatial mappings ("eddy events"). For high-Reynolds-number, wall-bounded flows relevant to the atmospheric boundary layer (ABL), resolving Kolmogorov scales is prohibitively expensive. This motivates careful implementation of wall models and subgrid scale models in ODT similar to large eddy simulations (LES).

Here, we develop an ODT formulation operated in an LES-like mode, in which unresolved eddy events are represented by a Smagorinsky–Lilly subgrid-scale (SGS) model, and surface coupling is provided through standard surface parametrisations for an extended range of resolved scales. We assess the formulation on two benchmark problems: (i) canonical smooth turbulent channel flow, using an algebraic wall model to supply surface stress consistent with resolved inertial-sublayer dynamics; and (ii) the GABLS1 intercomparison case (a weakly stable, shear-driven ABL with prescribed surface cooling rate), using Monin-Obukhov similarity theory to compute surface momentum and heat fluxes.

Together, these two cases demonstrate the feasibility of combining ODT's eddy-event transport with LES-style SGS and surface models, thus providing a computationally efficient platform for future studies of ABL regimes, in which turbulence, surface fluxes, entrainment across sharp inversions, and multi-phase physics interact and remain challenging for coarse-resolution weather and climate models.