HydroPy (v1.0): a new global hydrology model written in Python

Abstract. Global hydrological models (GHMs) are a useful tool in the assessment of land surface water balance. They used to further understanding interactions between balance components and their past evolution as well potential future development under various scenarios. While GHMs have been part hydrologist's toolbox for several decades, continuously being developed. In our study, we present HydroPy model, revised version an established GHM, Max Planck Institute Meteorology's Hydrology Model (MPI-HM). Being rewritten Python, new model requires much less effort maintenance, due its flexible infrastructure, processes can be easily implemented. Besides providing thorough documentation currently implemented HydroPy, demonstrate skill simulating We find that evapotranspiration is reproduced realistically majority but underestimated tropics. The simulated river discharge correlates with observations. Biases evident annual accumulated discharge; however, they – at least some extent attributed discrepancies meteorological forcing data Finally, show performs very similarly MPI-HM thus conclude successful transition from HydroPy.