Impact of Terrestrial Hydrology on L-A feedback and Isotope Signatures

Land-Atmosphere (L-A) interactions play a crucial role in current as well as future weather and climate. Since the resulting feedback mechanisms depend on L-A water pathways a sound understanding of the hereto related processes is required to depict them realistically in models and to further improve model performance. Stable water isotopes fungate as natural indicators of the hydrological cycle and can hence be used to assess the performance of climate models by comparing observational data with modeled isotope data.

Therefore, the fully coupled atmospheric hydrological modeling system WRF-Hydro-Iso with its innovative “-Iso” implementation is appropriate. Tracing water pathways with WRF-Hydro-Iso, we aim to improve our understanding of the relationship and interactions between groundwater, soil moisture, plant transpiration, soil evaporation, isotope signature and L-A feedback.

For a project domain in central Europe with a 5 km resolution the forcing data of ERA5 reanalysis and iCESM isotope climatology is used. In this session, first results of the WRF-Hydro-Iso modeled isotopes and L-A interactions are presented. The modeled isotopes are assessed with the TROPOMI atmospheric water Deuterium dataset, while L-A interactions are assessed with terrestrial water budgets and isotopic signatures of the water budget components.