New version of ESMValTool released

27 Mar 2020 - 4 min

Latest release features dramatic improvements in user-friendliness, reliability and performance.

A new version of the Earth System Model Evaluation Tool (ESMValTool) was recently made available to the scientific community. The release was announced by the ESMValTool development team, which includes the Netherlands eScience Center, in the first of four papers to be published in the journal Geoscientific Model Development. The latest version features dramatic improvements in user-friendliness, reliability and performance, as well as several new and improved features.

The Earth System Model Evaluation Tool (ESMValTool) is a community-based diagnostics and performance metrics tool for evaluating Earth System Models (ESM). It allows for routine comparison of single or multiple models, either against previous versions or against observations. The tool targets specific scientific themes and focuses on selected essential climate variables such as tropical climate variability, monsoons, atmospheric CO2 budgets, and tropospheric and stratospheric ozone. Its aim is to facilitate the analysis of data produced by earth system modelling groups within the Coupled Model Intercomparison Project (CMIP).

Keeping pace with advances in earth system modeling

Since the release of the ESMValTool in 2016, steady progress has been made in the field of earth system modelling, with future ESM experiments now expected to challenge the scientific community with an increasing volume of data that will need to be analysed, evaluated and interpreted. Moreover, the models’ higher spatial and temporal resolution combined with the growth of their scientific themes and complexity are making it difficult to carry out refined data analysis. 

“A major bottleneck of the ESMValtool 1 was the relatively inefficient preprocessing of the input data, leading to long computational times for running analyses and diagnostics whenever a large data volume needed to be processed”, says Bouwe Andela, eScience Research Engineer and a member of the ESMValTool development team. “A significant part of this preprocessing consists of common operations, which are performed on the input data before a specific scientific analysis is started. Ideally, these operations – collectively called preprocessing – should be centralized in the tool. This wasn’t the case with ESMValTool 1, where only a few of these preprocessing operations were performed in such a centralized way. This resulted in several drawbacks such as slow performance, code duplication, lack of consistency among the different approaches implemented at the diagnostic level, and unclear documentation.”

Faster and more user-friendly

The ESMValTool 2.0 was developed to address this bottleneck and features a new design with an improved interface and a revised preprocessor. Moreover, it includes a significantly enhanced diagnostic part and specifically targets the increased data volume and the related challenges posed by the analysis and the evaluation of output from multiple high-resolution or complex ESMs.

“The new version takes advantage of state-of-the-art computational libraries and methods to deploy efficient and user-friendly data processing. Common operations on the input data are centralized in a highly optimized preprocessor, which allows for applying a series of preprocessing functions before diagnostics scripts are applied for in-depth scientific analysis of the model output”, says Andela.

Performance tests conducted on a set of standard diagnostics also show that the new version is faster than its predecessor by about a factor of 30, depending on the hardware used. The development team was able to increase performance by introducing task-based parallelization options and expects to improve performance even further in the coming months. 

Andela: “I am really proud of what we as a team have produced. The latest version offers major improvements to both users and developers and allows for even more refined diagnostics and evaluation of earth system models. In the coming period, we’ll continue to build on this version and introduce new features.”

Publication details

Righi, M., Andela, B., Eyring, V., Lauer, A., Predoi, V., Schlund, M., Vegas-Regidor, J., Bock, L., Brötz, B., de Mora, L., Diblen, F., Dreyer, L., Drost, N., Earnshaw, P., Hassler, B., Koldunov, N., Little, B., Loosveldt Tomas, S., and Zimmermann, K.: Earth System Model Evaluation Tool (ESMValTool) v2.0 – technical overview, Geoscientific Model Development, 13, 1179–1199,, 2020.

Download the latest version of the ESMValTool
Read the full paper
Read more about the ESMValTool