Studies of land-atmosphere feedback with a new synergy of observing systems

In this presentation, a series of projects is presented and discussed to study land-atmosphere (L-A) interaction entirely based on measurements. The first effort, where a suitable sensor synergy was deployed for studying mainly the atmospheric leg, was the Land Atmosphere Feedback Experiment (LAFE) performed in August 2017 at the ARM SGP site. During this campaign, new tools where developed to derive turbulence and flux profiles, investigate flux-gradient relationship, retrieve surface fluxes using machine learning, measure feedback metrics using remote sensing instruments, and compare the observations with nested model simulations down to the turbulent scales. LAFE also demonstrated the importance of advection to investigate local and non-local feedback processes.

The successful performance of LAFE led to the establishment of the Land-Atmosphere Feedback Observatory (LAFO, see https://lafo.uni-hohenheim.de/en) at the University of Hohenheim, Stuttgart, Germany. Here, the LAFE observations are realized operationally so that larger data sets and their statistics can be evaluated. First results on feedback metrics over the heterogeneous agricultural landscape of LAFO will be presented.

These activities culminated in the GEWEX Land-Atmosphere Feedback Observatory (GLAFO), which is one of the projects of the Global Land-Atmosphere System Studies (GLASS) Panel (see https://www.gewex.org/panels/global-landatmosphere-system-study-panel/glass-projects). The GLAFO will observe mass, energy, water, and momentum transport with unprecedented spatial and temporal resolutions, from bedrock to the lower troposphere encompassing the atmospheric boundary layer (ABL). The vision of GLAFO is to establish LAFOs in different climate zones over the Earth in order to study L-A feedback from the diurnal cycle, via seasonal/annual to ideally climatological time scales.