|Beschreibung||The topsoil is a critical transition zone between soil and atmosphere, where important processes like infiltration and evaporation take place that control the water balance in the soil-(plant)-atmosphere continuum. For evaporation from bare soils, theoretical considerations and laboratory experiments suggest the formation of a very dry surface layer that hampers further evaporation due to the break of liquid film continuity from the subsoil to the atmosphere. Since this layer is relatively thin (up to a few cm only), the investigation of this dry layer requires a non-invasive monitoring technique with high resolution, as is provided by single sided NMR (nuclear magnetic resonance). In this master thesis, a NMR sensor will be used to monitor topsoil moisture dynamics at the Selhausen test site (bare soil test site). Monitoring results will be compared to soil-physical model calculations in order to investigate if the formation of a thin dry layer at the soil surface has to be considered under realistic outdoor conditions.|
This thesis requires your willingness to come to and work in the Forschungszentrum Jülich for six months.