Evolution of the convective boundary layer in connection with land-atmosphere interactions at the Land Atmosphere Feedback Observatory in Stuttgart-Hohenheim

Abstract

The land surface strongly influences the evolution of turbulence in and the energy exchange with the planetary boundary layer (PBL). High-resolution model simulations provide detailed insights into the evolving processes. We apply the WRF-NOAHMP model system in a nested configuration from the mesoscale (1.25 km) down to the LES scale (10 m). Driven by the ECMWF operational analysis, this setup allows high-resolution simulations with realistic lower boundary and meteorological forcing. A consistent set of physical parameterizations is applied through the whole chain of domains. Applying this setup, the evolution of the planetary boundary layer and land-atmosphere (L-A) feedback were investigated in detail for a selected day around the Land-Atmosphere-Feedback Observatory (LAFO) in Hohenheim. Apart from the evolution of the boundary layer at different horizontal resolutions, another focus is set on the derivation of turbulence variables and its comparison with data from lidar systems operated at the LAFO observatory on that day. The comparisons revealed that the high-resolution simulations in turbulence-permitting and LES scale realistically represent the temporal and spatial evolution of the convective boundary layer including the transitions between the nighttime and daytime boundary layers. Time-height cross sections of turbulence variables and fluxes are compared with lidar data and first results are presented on the meeting.