OpenBench: a land model evaluation system

Abstract. Recent land surface models (LSMs) have evolved significantly in complexity and resolution, requiring comprehensive evaluation systems to assess their performance. This paper introduces the Open Source Land Surface Model Benchmarking System (OpenBench), an open-source, cross-platform benchmarking system designed to evaluate the state-of-the-art LSMs. OpenBench addresses significant limitations in the current evaluation frameworks by integrating processes that encompass human activities, facilitating arbitrary spatiotemporal resolutions, and offering comprehensive visualization capabilities. The system utilizes various metrics and normalized scoring indices, enabling a comprehensive evaluation of different aspects of model performance. Key features include automation for managing multiple reference datasets, advanced data processing capabilities, and support for station-based and gridded data evaluations. By examining case studies on river discharge, urban heat flux, and agricultural modeling, we illustrate OpenBench's ability to identify the strengths and limitations of models across different spatiotemporal scales and processes. The system's modular architecture enables seamless integration of new models, variables, and evaluation metrics, ensuring adaptability to emerging research needs. OpenBench provides the research community with a standardized, extensible framework for model assessment and improvement. Its comprehensive evaluation capabilities and efficient computational architecture make it a valuable tool for both model development and operational applications in various fields.