Search

We investigate the reproduction of observed river discharge in a coupled system consisting from a regional climate model (RCM) and a distributed hydrology model (HM), where the HM is applied to route the runoff simulated by the RCM. The coupled system joins MPI and OpenMP based parallel codes of the COSMO-CLM (CCLM) regional climate model version 5 and the hydrology model WaSiM-ETH version 9 within the coupling environment provided by the OpenPALM model coupler.Application area is the complex terrain catchment of the Ammer River (600 km2) located in the Ammergau Alps in Southern Germany, where the HM runs on a 100 m grid in UTM projection with RCM input on rotated grid coordinates that is received every full model hour and interpolated on to this grid by the IDW method. Our contribution addresses general issues of hydrological simulations driven with biased RCM data input. Then it presents the coupled model system, its advantages and limitations, and the evaluation of the obtained results in comparison with measurements from river gauges and climate stations operated within the long term TERENO preAlpine observatory. Special attention is given to the investigation of periods with extremely high river flows applying highly resolved RCM runs in convection permitting mode at 0.03 degree and 0.01 degree grids. [ABSTRACT FROM AUTHOR]

The spatial and temporal distribution of soil water is a key constituent for the coupled moisture processes between the land surface and the atmospheric boundary layer. The scales of soil moisture observations and simulations with land-surface models are typically mismatching with respect to spatial support. Cosmic-ray neutron sensing (CRNS) offers a competitive method to observe soil moisture at the spatial scales of modern LSMs as typically used in local area climate and atmospheric models. In our study, we investigate how the assimilation of CRNS observations helps to improve the spatial structures of soil moisture in these models and the local soil moisture – atmospheric boundary layer interaction. The modeling chain consists of Noah-MP LSM, the WRF-Hydro model in both, observation driven and fully WRF coupled configuration, and the Data Assimilation Research Testbed (DART) coupled to WRF-Hydro (Hydro-DART). The data assimilation is based on Ensemble-Kalman Fitler (EnKF) with the fully coupled WRF-Hydro-Dart model system.Extensive observations from the Terrestrial Environmental Observatories (TERENO, www.tereno.net), will be used along with data from MOSES (Helmholtz Modular Observation Solutions for Earth Science https://moses.eskp.de/), and with data from the DFG research unit Cosmic Sense. We present the structure and a first evaluation of the model system for the Ammer river catchment in southern Germany based on observations from the TERENO preAlpine network. [ABSTRACT FROM AUTHOR]