The Land-Atmosphere Feedback Experiment (LAFE)

Description

Feedbacks between the land surface and the atmosphere determine the evolution of the atmospheric boundary layer (ABL) and thus, the evolution of clouds and precipitation. Therefore, the understanding and correct simulation of land-atmosphere (LA) feedback is critical for the performance of numerical weather prediction (NWP) and climate models. However, there are only a few data sets that exist for measuring LA feedback directly for the verification and improvement of models. This is due to the fact that the state of the soil, the vegetation, and the ABL, as well as the transport of momentum, heat, and water vapor, have to be measured simultaneously in this coupled system, which is a challenging effort. The Land-Atmosphere Feedback Experiment (LAFE) will deploy several state of-the-art scanning lidar and remote-sensing systems to the ARM Southern Great Plains (SGP) site. These instruments will augment the ARM instrument suite in order to collect an advanced data set for studying feedback processes in the LA system. The novel synergy of remote-sensing systems will be applied for simultaneous measurements of land-surface fluxes and horizontal and vertical transport processes in the atmospheric convective boundary layer (CBL). The impact of spatial inhomogeneities of the soil-vegetation continuum on LA feedback will be studied using the scanning capability of the instrumentation. The field experiment will be conducted in August, 2017 when large differences in surface fluxes between different fields and bare soil are expected, e.g., between pastures versus fields where the wheat has already been harvested. In this presentation, the LAFE sensor synergy and the measurement concept will be introduced. The combination of the LAFE instrumental components will enable us to estimate the moisture budget in the SGP domain. Based on the results of previous campaigns, the measurements can also be applied for the development of improved parameterizations of surface fluxes and turbulence in the CBL. The results will be used for the verification of large-eddy simulation (LES) and mesoscale models, which are planned for the SGP site. Thus, this new generation of experiments can strongly contribute to the improvement of the parameterization of key processes in weather, climate, and earth system models.