It is difficult to directly assess the infiltration schemes at the operational scales of numerical weather forecasts and hydrometeorological applications, as no direct measurements of infiltration are typically available. Observational datasets of evapotranspiration, soil moisture contents, and streamflow are relevant but not only related to infiltration. To reveal the sources of uncertainty possibly brought by the infiltration schemes, we present an intercomparison study of LSMs from the perspective of infiltration. The study is based on the software framework of the NASA Land Information System (LIS), which has an array of LSMs integrated, for example, JULES, Noah-MP, Noah, and VIC. These models use different physical or conceptual schemes to describe the infiltration process.
In this study, we compare the throughfall and infiltration outputs from the four LSMs. All analyses are conducted with the NLDAS Science Testbed, in which LIS runs over the NLDAS domain with the same forcing data. The results of this study provide important insights into understanding the infiltration behavior of these models. Such insights will be helpful for evaluating uncertainties in streamflow, evapotranspiration, and estimates of hydrologic extremes simulated with various LSMs and modeling systems.