Adaptation of the meteorological model Meso-NH to laboratory experiments: implementations and validation

Abstract. A meteorological numerical model can be a powerful tool to complement laboratory experiments applied to atmospheric sciences, but it needs to be adapted in order to represent flows generated in laboratory. This paper presents such an adaptation of the atmospheric non-hydrostatic model Meso-NH. The usually neglected viscous diffusive fluxes have been added to the model’s equations, along with the coding of an explicit bottom no-slip boundary condition was implemented. These implementations are validated against exact solutions of ideal flows. Meso-NH is then used in a configuration matching a laboratory experiment performed in the CNRM large stratified water flume meant to reproduce a neutral atmospheric boundary layer. The model is run for the first time in an explicit mode (Direct Numerical Simulation – DNS) at a very high resolution (1 mm) over a large grid. The comparison with the experimental data shows that the boundary layer height and vertical profiles of mean velocity are well captured by the model. This result further validates the implementations carried out in Meso-NH which can now be used in a DNS mode to simulate channel flows. The joint use of Meso-NH and laboratory experiments, along with the possibility to run DNS with Meso-NH, could lead to new findings or improvements in the field of atmospheric sciences.