NMH-CS 3.0: a C# programming language and Windows-system-based ecohydrological model derived from Noah-MP

Abstract

The community Noah with multi-parameterization options (Noah-MP) land surface model (LSM) is widely used in studies ranging from uncoupled land surface hydrometeorology and ecohydrology to coupled weather and climate predictions. In this study, we developed NMH-CS 3.0, a hydrological model written in C# (pronounced C sharp). NMH-CS 3.0 is a new model developed by faithfully translating Noah-MP, written in Fortran, from the uncoupled WRF-Hydro 3.0, and it is coupled with a river routing model. NMH-CS has the capacity to be executed on Windows systems, utilizing the multi-core CPUs commonly available in today's personal computers. The code of NMH-CS has been tested to ensure that it produces a high degree of consistency with the output of the original WRF-Hydro. High-resolution (6 km) simulations were conducted and assessed over a grid domain covering the entire Yellow River basin and most of northern China. The spatial maps and temporal variations in many state variables simulated by NMH-CS 3.0 and WRF-Hydro/Noah-MP demonstrate highly consistent results, occasionally with minor discrepancies. The river discharge for the Yellow River simulated by the new model with various scheme combinations of six parameterizations exhibits general agreement with the natural river discharge at the Lanzhou station. NMH-CS can be regarded as a reliable replica of Noah-MP in WRF-Hydro 3.0, but it can leverage the modern, powerful, and user-friendly features brought by the C# language to significantly improve the efficiency of the model's users and developers.