Annual ETCCDI Extreme Indices For ICON-Sapphire And IFS-FESOM (nextGEMS Cycle 4)

Project: Cluster of Excellence “Climate, Climatic Change, and Society” - CLICCS will explore climate change with broad expertise. CLICCS will investigate how the climate changes and how society changes with it, thereby feeding back on climate. Understanding these changes, including how societies adapt, will enable us to assess with far greater confidence than before the range of imaginable climate futures. In taking on this challenge, CLICCS is guided by the overarching question: "Which climate futures are possible and which are plausible?"
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Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - EXC 2037 'CLICCS - Climate, Climatic Change, and Society' - Project Number: 390683824. Contribution to the Center for Earth System Research and Sustainability (CEN) of Universität Hamburg.
Summary: ETCCDI indices calculated from two km-scale global models developed within the nextGEMS project (https://nextgems-h2020.eu/): ICON-Sapphire (Hohenegger et al. 2023) and IFS-FESOM (Rackow et al. 2025). The indices are based on the 30-year production simulations of nextGEMS, cycle 4 with a spatial resolution of about 10km (Segura et al. 2025). Here, we provide them in the 29-year period 2021-2049 (as the first year, 2020, is incomplete for IFS), driven by the high-emission pathway SSP3-7.0.
The original data and the derived indices are available on the unstructured HEALPix grid (Górski et al. 2005). HEALPix organises data at discrete resolutions or zoom levels. Here, the highest resolved zoom level 9 (about 13km grid spacing corresponding to about 3 million grid cells globally) and the intermediate (“CMIP6-like”) zoom level 6 (about 102km, 50’000 grid cells) are provided.

The data were processed by Lukas Brunner (https://orcid.org/0000-0001-5760-4524), using a Climate Data Operators (https://code.mpimet.mpg.de/projects/cdo/embedded/index.html) implementation of the ETCCID indices: code on GitHub (https://doi.org/10.5281/zenodo.15582463).
Time-mean plots of all indices are available on Zenodo: https://doi.org/10.5281/zenodo.15613611

If you use the indices, please cite this dataset and the accompanying publication:
Brunner L., B. Poschlod, E. Dutra, E. M. Fischer, O. Martius, and J. Sillmann (2025): A global perspective on the spatial representation of climate extremes from km-scale models. Environmental Research Letters, https://doi.org/10.1088/1748-9326/ade1ef