A fully revised version of the Earth System Model Evaluation Tool (ESMValTool v2.0) was recently made available to the scientific community. The release was made possible by a shared effort of the international ESMValTool development team, which consists of about 200 developers from 70 institutions.
The ESMValTool is a community-developed diagnostics and performance metrics tool for evaluating Earth System Models (ESMs). ESMs are important tools not only to improve our understanding of present-day climate but also to project climate change under different plausible future scenarios. For this, climate models have been continuously improved and extended over the last decades from relatively simple atmosphere-only models to today’s complex state-of-the-art ESMs. The aim of the ESMValTool is to facilitate the analysis of data from these models and to provide first results much faster than was possible before. The ESMValTool is one of the tools used for analysis and contributions to the new Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6) currently in preparation.
The latest version of the ESMValTool features dramatic improvements in performance, reliability and user-friendliness as well as several new and improved features such as extended documentation of code and scientific diagnostics and detailed provenance tracking to ensure traceability and reproducibility of the results. ESMValTool v2.0 has been developed to specifically target the increased data volume of model intercomparison projects such as the Coupled Model Intercomparison Project Phase 6 (CMIP6) and the related challenges posed by analysis and evaluation of output from multiple high-resolution and complex ESMs. For this, the core functionalities of the ESMValTool have been completely rewritten in order to take advantage of state-of-the-art computational libraries and methods to allow for efficient and user-friendly data processing by a highly optimized preprocessor written in Python. New diagnostics available in v2.0 include an extended set of large-scale diagnostics for quasi-operational and comprehensive evaluation of ESMs, diagnostics for extreme events, regional model and impact evaluation and analysis of ESMs, as well as diagnostics for emergent constraints and analysis of future projections from ESMs.
Example analysis of data from the Coupled Model Intercomparison Project Phase 6 with the ESMValTool showing observed and simulated time series of anomalies in annual and global mean surface temperature. All anomalies are differences from the 1850-1900 time-mean of each individual time series. The reference period is indicated by gray shading. The thin lines show individual climate model simulations, the thick red line shows the multi-model mean. The observational data (thick black line) are the Hadley Centre/Climatic Research Unit gridded surface temperature data set version 4 (HadCRUT4). All models have been subsampled using the HadCRUT4 observational data mask. The inset (right) shows the global mean surface temperature for the reference period 1850-1900 of the subsampled fields.
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, Geosci. Model Dev., 13, 1179-1199, doi: 10.5194/gmd-13-1179-2020, 2020. Eyring, V., Bock, L., Lauer, A., Righi, M., Schlund, M., Andela, B., Arnone, E., Bellprat, O., Brötz, B., Caron, L.-P., Carvalhais, N., Cionni, I., Cortesi, N., Crezee, B., Davin, E., Davini, P., Debeire, K., de Mora, L., Deser, C., Docquier, D., Earnshaw, P., Ehbrecht, C., Gier, B. K., Gonzalez-Reviriego, N., Goodman, P., Hagemann, S., Hardiman, S., Hassler, B., Hunter, A., Kadow, C., Kindermann, S., Koirala, S., Koldunov, N. V., Lejeune, Q., Lembo, V., Lovato, T., Lucarini, V., Massonnet, F., Müller, B., Pandde, A., Pérez-Zanón, N., Phillips, A., Predoi, V., Russell, J., Sellar, A., Serva, F., Stacke, T., Swaminathan, R., Torralba, V., Vegas-Regidor, J., von Hardenberg, J., Weigel, K., and Zimmermann, K.: Earth System Model Evaluation Tool (ESMValTool) v2.0 - an extended set of large-scale diagnostics for quasi-operational and comprehensive evaluation of Earth system models in CMIP, Geosci. Model Dev., 13, 3383-3438, doi: 10.5194/gmd-13-3383-2020, 2020. Lauer, A., Eyring, V., Bellprat, O., Bock, L., Gier, B. K., Hunter, A., Lorenz, R., Pérez-Zanón, N., Righi, M., Schlund, M., Senftleben, D., Weigel, K., and Zechlau, S.: Earth System Model Evaluation Tool (ESMValTool) v2.0 – diagnostics for emergent constraints and future projections from Earth system models in CMIP, Geosci. Model Dev., 13, 4205-4228, doi: 10.5194/gmd-13-4205-2020, 2020. Weigel et al.: ESMValTool (v2.0) - Diagnostics for extreme events, regional model and impact evaluation and analysis of Earth system models in CMIP, submitted (Geosci. Model Dev.).