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

Identification

• Journal: Open MIND
• Year: 2025
• Date: 2025-11-24
• Authors: Jürgen Kröger, Chathurika Wickramage, Fabian Wachsmann
• DOI: 10.26050/wdcc/eerieiconhist_v1

Research Groups

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

Short Summary

This paper describes the generation and characteristics of a 65-year historical climate simulation dataset (1950-2014) using the ICON-Sapphire Earth System Model, which explicitly resolves ocean mesoscale dynamics at kilometer-scale resolution to improve long-term climate simulations.

Objective

• To generate a high-resolution, eddy-rich historical climate simulation dataset (1950-2014) using the ICON-Sapphire Earth System Model to advance the understanding and prediction of climate variability, extremes, and potential tipping points influenced by mesoscale ocean processes.

Study Configuration

• Spatial Scale: Global, with kilometer-scale resolution explicitly resolving ocean mesoscale to sub-mesoscale eddies.
• Temporal Scale: A 40-year spin-up period, followed by a 100-year control run and a 65-year historical simulation (1950-01-01 to 2014-12-31).

Methodology and Data

• Models used:
  • ICON (Icosahedral Nonhydrostatic) in Sapphire configuration: A coupled Earth System Model integrating atmosphere, land, ocean, and sea ice components.
  • Atmospheric component: Nonhydrostatic icosahedral C grid with hybrid sigma-z vertical coordinate.
  • Ocean component: Hydrostatic Boussinesq equations, sharing the same grid as the atmosphere.
  • Sea ice component: FESIM dynamics with a simplified thermodynamic scheme.
  • Ocean biogeochemistry: HAMOCC6, simulating over 20 tracers.
  • Land component: JSBACH 4, providing surface fluxes and simplified hydrology with prescribed vegetation.
  • Coupler: YAC coupler (v2.4.2).
• Data sources:
  • CMIP6 forcing for the spin-up and historical simulations.
  • CMIP5 volcanic aerosol forcing.

Main Results

• A comprehensive 65-year historical climate simulation dataset (1950-2014) was successfully generated using the ICON-Sapphire Earth System Model, featuring kilometer-scale resolution and explicit representation of ocean mesoscale dynamics.
• The dataset, totaling 23.45 terabytes, includes a wide array of atmospheric, oceanic, land, and sea ice variables, with specific corrections for geopotential height variables in a later version (v20240619).
• The simulation process involved a 40-year spin-up period and a parallel 100-year control run to identify and quantify model drift, ensuring the reliability of the historical simulation's long-term changes.

Contributions

• Development and application of the ICON-Sapphire Earth System Model, representing a new generation of ESMs capable of explicitly resolving ocean mesoscale dynamics at kilometer-scale resolution.
• Provision of a unique, high-resolution, eddy-rich historical climate simulation dataset (1950-2014) to the scientific community, which is crucial for improving the understanding of climate variability, extremes, and potential tipping points.
• This dataset serves as a foundational component for the EERIE project's overarching goal of advancing long-term climate simulations by incorporating previously unresolved 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: Historical Simulation (Version 1)},
  journal = {Open MIND},
  year = {2025},
  doi = {10.26050/wdcc/eerie_icon_hist_v1},
  url = {https://doi.org/10.26050/wdcc/eerie_icon_hist_v1}
}