The Earth system model CLIMBER-X v1.0 – Part 1: Climate model description and validation

• Published in: Geoscientific Model Development
• Main Authors: Willeit, Matteo, Ganopolski, Andrey, Robinson, Alexander, Edwards, Neil R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications (EGU) 2022
• Subjects: Ice Sheet; Sea ice
• Online Access: https://oceanrep.geomar.de/id/eprint/57252/; https://oceanrep.geomar.de/id/eprint/57252/1/gmd-15-5905-2022.pdf; https://doi.org/10.5194/gmd-15-5905-2022

The newly developed fast Earth system model CLIMBER-X is presented. The climate component of CLIMBER-X consists of a 2.5-D semi-empirical statistical–dynamical atmosphere model, a 3-D frictional–geostrophic ocean model, a dynamic–thermodynamic sea ice model and a land surface model. All the model components are discretized on a regular lat–long grid with a horizontal resolution of . The model has a throughput of ∼ 10 000 simulation years per day on a single node with 16 CPUs on a high-performance computer and is designed to simulate the evolution of the Earth system on temporal scales ranging from decades to >100 000 years. A comprehensive evaluation of the model performance for the present day and the historical period shows that CLIMBER-X is capable of realistically reproducing many observed climate characteristics, with results that generally lie within the range of state-of-the-art general circulation models. The analysis of model performance is complemented by a thorough assessment of climate feedbacks and model sensitivities to changes in external forcings and boundary conditions. Limitations and applicability of the model are critically discussed. CLIMBER-X also includes a detailed representation of the global carbon cycle and is coupled to an ice sheet model, which will be described in separate papers. CLIMBER-X is available as open-source code and is expected to be a useful tool for studying past climate changes and for the investigation of the long-term future evolution of the climate.