The study is investigates modelling of land surface – atmosphere interactions in context of fully coupled climatehydrological
model. With a special focus of under what condition a fully coupled model system is needed.
Regional climate model inter-comparison projects as ENSEMBLES have shown bias related to inaccurate land
surface modelling, e.g. enhanced warm bias in warm dry summer months. Coupling the regional climate model
to a hydrological model shows the potential of improving the surface flux simulations in dry periods and the 2 m
air temperature in general. In the dry periods representation of groundwater in the hydrological model is found
to important and this imply resolving the small river valleys. Because, the important shallow groundwater is
found in the river valleys. If the model does not represent the shallow groundwater then the area mean surface
flux calculation by the hydrological model is found to be insensitive to model resolution. Furthermore, this study
highlights the effect of bias precipitation by regional climate model and it implications for hydrological
modelling.