The effects of spatial and temporal resolution of gridded meteorological forcing on watershed hydrological responses

Abstract. Meteorological forcing plays a critical role in accurately simulating the watershed hydrological cycle. With advancement of high-performance computing and development integrated models, cycle at high temporal (hourly to daily) spatial resolution (tens meters) has become efficient computationally affordable. These hyperresolution models require meteorological as model input ensure fidelity accuracy simulated responses. In this study, we utilized Advanced Terrestrial Simulator (ATS), an model, simulate surface subsurface flow land processes using unstructured meshes Coal Creek Watershed near Crested Butte (Colorado). We compared hydrologic responses including streamflow distributed variables such evapotranspiration, snow water equivalent (SWE), groundwater table driven by three publicly available, gridded forcings (GMFs) – Daily Surface Weather Climatological Summaries (Daymet), Parameter-elevation Regressions on Independent Slopes Model (PRISM), North American Land Data Assimilation System (NLDAS). By comparing various resolutions (ranging from 400 m 4 km) PRISM, only becomes marginally worse when is coarsened km (or 30 % area). However, km-resolution much performance than finer spatially SWE. Using temporally disaggregated forced different daily), sub-daily preserves dynamic (e.g., diurnal fluctuation streamflow) that are absent results daily resolution. Conversely, shows better Our findings suggest choice GMF its spatiotemporal depends quantity interest scale, which may have important implications for calibration management decisions.