Kröger et al. (2025) EERIE: Ocean Eddy-rich Kilometer-scale Climate Simulation with ICON: SSP2-4.5 Scenario Simulation (Version 1)

Identification

• Journal: Open MIND
• Year: 2025
• Date: 2025-11-24
• Authors: Jürgen Kröger, Chathurika Wickramage, Fabian Wachsmann
• DOI: 10.26050/wdcc/eerieicons245_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 of a kilometer-scale, eddy-rich global climate simulation dataset using the ICON Earth System Model for the SSP2-4.5 scenario pathway from 2015 to 2050, aiming to improve long-term climate projections by explicitly resolving ocean mesoscale dynamics.

Objective

• To provide a comprehensive, kilometer-scale, eddy-rich Earth System Model simulation dataset for the SSP2-4.5 scenario pathway to 2050, enabling improved understanding of climate variability, extremes, and potential tipping points influenced by mesoscale ocean processes.

Study Configuration

• Spatial Scale: Global (Longitude 0 to 360 degrees, Latitude -90 to 90 degrees) with kilometer-scale resolution, explicitly resolving ocean mesoscale to sub-mesoscale eddies.
• Temporal Scale: A 40-year spin-up (using 1950 CMIP6 forcing), followed by a 100-year control run and a historical run. The main scenario simulation extends from 2015-01-01 to 2050-12-31 under CMIP6 SSP2-4.5 forcings.

Methodology and Data

• Models used: ICON (Sapphire configuration) Earth System Model, which couples atmosphere, land, ocean, and sea ice.
  • Atmospheric component: ICON (nonhydrostatic icosahedral C grid, hybrid sigma-z vertical coordinate).
  • Oceanic component: ICON (same grid, hydrostatic Boussinesq equations, with parameterizations for vertical mixing and velocity dissipation).
  • Sea Ice component: FESIM dynamics and a simplified thermodynamic scheme.
  • Ocean Biogeochemistry: HAMOCC6 (simulating over 20 tracers).
  • Land component: JSBACH 4 (providing surface fluxes and simplified hydrology).
  • Coupler: YAC coupler (v2.4.2).
• Data sources: CMIP6 scenario forcings were used for the spin-up, historical, and SSP2-4.5 scenario simulations. The output is a dataset of simulated climate variables.

Main Results

• A comprehensive, eddy-rich, kilometer-scale global climate simulation dataset has been generated for the SSP2-4.5 scenario, covering the period from 2015 to 2050.
• The dataset includes a wide range of atmospheric, oceanic, land, and sea ice variables at various temporal resolutions (e.g., 6-hourly, daily, monthly).
• The simulation was carefully initialized with a 40-year spin-up and validated against a 100-year control run to identify and quantify model drift.

Contributions

• Provides a novel, high-resolution (kilometer-scale) Earth System Model simulation dataset that explicitly resolves ocean mesoscale dynamics, a crucial but poorly explored part of the climate system.
• Offers unprecedented detail for estimating near-future climate change (to 2050) under the SSP2-4.5 scenario.
• Contributes to the development of a new generation of Earth System Models within the EERIE project, aiming to improve the representation of climate variability, extremes, and potential tipping points.

Funding

• European Commission - Horizon Europe Grant/Award No: 101081383 - European Eddy-RIch Earth System Models (EERIE)

Citation

@article{Kröger2025EERIE,
  author = {Kröger, Jürgen and Wickramage, Chathurika and Wachsmann, Fabian},
  title = {EERIE: Ocean Eddy-rich Kilometer-scale Climate Simulation with ICON: SSP2-4.5 Scenario Simulation (Version 1)},
  journal = {Open MIND},
  year = {2025},
  doi = {10.26050/wdcc/eerie_icon_s245_v1},
  url = {https://doi.org/10.26050/wdcc/eerie_icon_s245_v1}
}