nextGEMS: entering the era of kilometer-scale Earth system modeling
Creators: name: Segura, Hans
name: Pedruzo-Bagazgoitia Xabier
name: Weiss, Philipp
name: Müller Sebastian, K.
name: Rackow, Thomas
name: Lee, Junhong
name: Dolores Tesillos, Edgar
name: Benedict, Imme
name: Aengenheyster, Matthias
name: Aguridan, Razvan
name: Arduini, Gabriele
name: Baker, Alexander J.
name: Bao, Jiawei
name: Bastin, Swantje
name: Baulenas, Eulàlia
name: Becker, Tobias
name: Beyer, Sebastian
name: Bockelmann, Hendryk
name: Brüggemann, Nils
name: Brunner, Lukas
name: Cheedela Suvarchal, K.
name: Das, Suhas
name: Denissen, Jasper
name: Dragaud, Ian
name: Dziekan, Piotr
name: Ekblom, Madeleine
name: Engels, Jan Frederik
name: Esch, Monika
name: Forbes, Richard
name: Frauen, Claudia
name: Freischem Lilli J
name: García-Maroto Diego
name: Geier, Philipp
name: Gierz, Paul
name: González-Cervera, Álvaro
name: M, Grayson Katherine
name: Griffith, Matthew
name: Gutjahr, Oliver
name: Haak, Helmuth
name: Hadade, Ioan
name: Haslehner, Kerstin
name: Hasson Shabeh Ul
name: Hegewald, Jan
name: Kluft, Lukas
name: Koldunov, Aleksei
name: Koldunov Nikolay, V.
name: Kölling, Tobias
name: Koseki, Shunya
name: Kosukhin, Sergey
name: Kousal, Josh
name: Kuma, Peter
name: Kumar, Arjun U.
name: Li, Rumeng
name: Maury, Nicolas
name: Meindl, Maximilian
name: Milinski, Sebastian
name: Mogensen Kristian, S.
name: Niraula, Bimochan
name: Nowak, Jakub
name: Praturi Divya Sri
name: Proske, Ulrike
name: Putrasahan, Dian
name: Redler, Rene
name: Santuy, David
name: Sármány, Domokos
name: Schnur, Reiner
name: Scholz, Patrick
name: Sidorenko, Dmitry
name: Spät, Dorian
name: Sützl, Birgit
name: Takasuka, Daisuke
name: Tompkins, Adrian
name: Uribe Cortes Alejandro
name: Valentini, Mirco
name: Veerman, Menno
name: Voigt, Aiko
name: Warnau, Sarah
name: Wachsmann, Fabian
name: Waclawczyk, Marta
name: Wedi, Nils
name: Wieners Karl-Hermann
name: Wille, Jonathan
name: Winkler, Marius
name: Wu, Yuting
name: Ziemen Florian Andreas
name: Zimmermann, Janos
name: Bender, Frida
name: Bojovic, Dragana
name: Bony, Sandrine
name: Bordoni, Simona
name: Brehmer, Patrice
name: Dengler, Marcus
name: Dutra, Emanuel
name: Faye, Saliou
name: Fischer, Erich
name: Van Heerwaarden Chiel, 
name: Hohenegger, Cathy
name: Järvinen, Heikki
name: Jochum, Markus
name: Jung, Thomas
name: Jungclaus, Johann H.
name: Keenlyside, Noel
name: Klocke, Daniel
name: Konow, Heike
name: Klose, Martina
name: Malinowski, Szymon
name: Martius, Olivia
name: Mauritsen, Thorsten
name: Mellado, Juan Pedro
name: Mieslinger, Theresa
name: Mohino, Elsa
name: Pawlowska, Hanna
name: Peters-Von Gehlen Karsten
name: Sarré, Abdoulaye
name: Sobhani, Pajam
name: Stier, Philip
name: Tuppi, Lauri
name: Vidale Pier Luigi
name: Sandu, Irina
name: Stevens, Bjorn
Publisher: name: University of Bern
publisherIdentifier: https://ror.org/02k7v4d05
publisherIdentifierScheme: ROR
Year: 2025
Subjects: nextGEMS

description: The Next Generation of Earth Modeling Systems (nextGEMS) project aimed to produce multi-decadal climate simulations, for the first time, with resolved kilometer-scale (km-scale) processes in the ocean, land, and atmosphere. In only three years, nextGEMS achieved this milestone with the two km-scale Earth system models, ICOsahedral Non-hydrostatic model (ICON) and Integrated Forecasting System coupled to the Finite-volumE Sea ice-Ocean Model (IFS-FESOM). nextGEMS was based on three cornerstones: 1) developing km-scale Earth system models with small errors in the energy and water balance, 2) performing km-scale climate simulations with a throughput greater than one simulated year per day, and 3) facilitating new workflows for an efficient analysis of the large simulations with common data structures and output variables. These cornerstones shaped the timeline of nextGEMS, divided into four cycles. Each cycle marked the release of a new configuration of ICON and IFS-FESOM, which were evaluated at hackathons. The participants in hackathons included experts from climate science, software engineering, and high-performance computing, as well as users from the energy and agricultural sectors. The continuous efforts over the four cycles allowed us to produce 30-year simulations of ICON and IFS-FESOM, spanning the period 2020–2049 under the SSP3-7.0 scenario. The throughput was about 500 simulated days per day on the Levante supercomputer of the German Climate Computing Center (DKRZ). The simulations employed a horizontal grid of about 5 km resolution in the ocean and 10 km resolution in the atmosphere and land. Aside from this technical achievement, the simulations allowed us to gain new insights into the realism of ICON and IFS-FESOM. Beyond its timeframe, nextGEMS builds the foundation of the Climate Change Adaptation Digital Twin developed in the Destination Earth initiative and paves the way for future European research on climate change.
description: The nextGEMS project developed two Earth system models that resolve processes of the order of 10 km, giving more fidelity to the representation of local phenomena, globally. In its fourth cycle, nextGEMS performed simulations with coupled ocean, land, and atmosphere over the 2020–2049 period under the SSP3-7.0 scenario. Here, we provide an overview of nextGEMS, insights into the model development, and the realism of multi-decadal, kilometer-scale simulations.