Kröger et al. (2025) EERIE: Ocean Eddy-rich Kilometer-scale Climate Simulation with ICON: Control Simulation (Version 1)

Identification

• Journal: Open MIND
• Year: 2025
• Date: 2025-11-24
• Authors: Jürgen Kröger, Chathurika Wickramage, Fabian Wachsmann
• DOI: 10.26050/wdcc/eerieiconctrl_v1

Research Groups

• Max Planck Institute for Meteorology
• Deutsches Klimarechenzentrum (DKRZ)
• European Eddy RIch Earth System Models (EERIE) project

Short Summary

This paper describes the generation and characteristics of a 100-year global control simulation using the kilometer-scale ICON-Sapphire Earth System Model, explicitly resolving ocean mesoscale dynamics. The primary purpose of this simulation is to quantify model drift, providing a crucial baseline for future historical climate simulations within the EERIE project.

Objective

• To generate a 100-year control simulation using the ICON-Sapphire Earth System Model to identify and quantify model drift, ensuring that long-term changes in subsequent historical simulations can be accurately attributed to external forcing rather than internal model biases.

Study Configuration

• Spatial Scale: Global (0 to 360 degrees longitude, -90 to 90 degrees latitude) with kilometer-scale resolution, including an option for local grid refinement ("computational telescope").
• Temporal Scale: A 40-year spin-up period (starting 1950) followed by a 100-year control run, covering 1950-01-01 to 2050-12-31.

Methodology and Data

• Models used: ICON (Icosahedral Nonhydrostatic) in Sapphire configuration, an Earth System Model (ESM) coupling atmosphere, land, ocean, and sea ice.
  • Atmospheric component: Nonhydrostatic icosahedral C grid with hybrid sigma-z vertical coordinate.
  • Ocean component: Hydrostatic Boussinesq equations on the same grid, with FESIM dynamics for sea ice and HAMOCC6 for ocean biogeochemistry (simulating >20 tracers).
  • Land component: JSBACH 4, providing surface fluxes and simplified hydrology.
  • Coupler: YAC coupler (v2.4.2).
• Data sources: 1950 CMIP6 forcing for the spin-up period. The output is a comprehensive dataset of the control simulation.

Main Results

• The successful completion and archiving of a 100-year global, eddy-rich, kilometer-scale control simulation dataset (Version 1) using the ICON-Sapphire model.
• This dataset, spanning 1950-01-01 to 2050-12-31, serves as a critical baseline for identifying and quantifying model drift, which is essential for the robust interpretation of future historical climate simulations.
• The simulation explicitly resolves deep atmospheric convection and mesoscale to sub-mesoscale ocean eddies, providing high-resolution climate data.

Contributions

• Provides a foundational 100-year control simulation dataset for the EERIE project, enabling the quantification of model drift in a new generation of eddy-rich, kilometer-scale Earth System Models.
• Advances climate modeling by utilizing the ICON-Sapphire model, which explicitly resolves ocean mesoscale dynamics and deep atmospheric convection, improving the representation of key climate processes.
• Facilitates the development of more accurate long-term climate simulations, including variability, extremes, and potential tipping points influenced by mesoscale ocean processes.

Funding

• European Commission - Horizon Europe, Grant/Award No: 101081383 - European Eddy-RIch ESMs (EERIE)

Citation

@article{Kröger2025EERIE,
  author = {Kröger, Jürgen and Wickramage, Chathurika and Wachsmann, Fabian},
  title = {EERIE: Ocean Eddy-rich Kilometer-scale Climate Simulation with ICON: Control Simulation (Version 1)},
  journal = {Open MIND},
  year = {2025},
  doi = {10.26050/wdcc/eerie_icon_ctrl_v1},
  url = {https://doi.org/10.26050/wdcc/eerie_icon_ctrl_v1}
}