© Forschungszentrum Jülich / Sascha Kreklau. Source: https://www.fz-juelich.de/en/newsroom-jupiter
A delegation from ECMWF attended the inauguration ceremony of JUPITER at the Forschungszentrum Jülich in Germany. ECMWF was represented by Director of Forecasts and Services and next Director-General Florian Pappenberger, Director for Destination Earth Irina Sandu, Digital Technology Lead for Destination Earth Nils Wedi, and Head of Earth System Modelling Peter Düben. ECMWF has been actively involved in the initial operations of the first exascale supercomputer in Europe and has deployed several simulations and experiments.
Officials from the European Commission and the German Federal and regional governments led the ceremony in front of international guests from politics, science and industry. It marked the end of the initial setup of the JUPITER (Joint Undertaking Pioneer for Innovative Exascale Research) supercomputer and its opening to new projects.
Representatives from the Jülich Supercomputing Centre, the European Commission and the German authorities at the symbolic start-up of the JUPITER supercomputer. Image: © Forschungszentrum Jülich / Kurt Steinhausen. Source: https://www.fz-juelich.de/en/newsroom-jupiter
Bringing Europe outstanding computing power
“It is very important that Europe is entering the era of exascale computing. We are in exciting times for numerical weather prediction with unprecedented developments in artificial intelligence and machine learning, and, at the same time, we are witnessing technology achievements such as JUPITER that put in our hands extraordinary computing power. Combined with new observation capabilities and the fast-evolving scientific developments in the areas of weather and climate, this computer power will mark a fundamental step-change in the products we deliver to our Member States and partners. Our congratulations to colleagues at FZ-Jülich and the European High-Performance Computing Joint Undertaking (EuroHPC-JU), the German Federal Ministry of Research and the Ministry of Culture and Science of North Rhine-Westphalia, who have funded the most powerful machine in Europe,” said Director of Forecasts and Services and ECMWF’s Director-General Elect, Florian Pappenberger.
ECMWF has run a number of simulations and experiments on the flagship European supercomputer since being selected to run a project under the GCS Exascale Pioneer Call issued by the Gauss Centre for Supercomputing as a part of the JUPITER Research and Early Access Program (JUREAP). The project “Jupiter meets Europa – Extreme ExaScale Global Weather Forecasting for a changing climate (JEuExa)” was approved by the GCS evaluation committee in January 2025.
The Call grants ECMWF 414,000 node hours on the JUPITER Booster module, the first exascale supercomputer installed in Europe. An additional 300,000 node hours are granted as part of ECMWF activities in the Destination Earth initiative (DestinE) of the European Commission, selected as one of the EuroHPC JU Lighthouse projects.
Additionally, ECMWF was awarded 350,000 node hours with the proposal "Global Kilometer-scale Probabilistic Data-driven Modelling" in the Gauss AI Compute Competition. The successful team will train a data-driven probabilistic forecasting system at high resolution, based on previous developments at ECMWF in the Destination Earth initiative and the work with the Artificial Intelligence Forecasting System (AIFS), ECMWF’s data-driven forecasting system.
The Booster module consists of about 6,000 nodes, each using four NVIDIA GH200 Superchips. Each NVIDIA GH200 Superchip contains one 72-core NVIDIA Grace ARM-based CPU and one NVIDIA H100 GPU in a tightly integrated package. The JUPITER Booster module will be the first in Europe to provide 1 exaflop performance, surpassing the threshold of one quintillion (“1” followed by 18 zeros) calculations per second, and even more when used in AI applications. For comparison, the current most powerful machine in Europe, LUMI, has a sustained performance of 386 petaflops.
The supercomputer will contribute to Europe’s AI Factory ecosystem promoted by the European Commission and the EuroHPC.
JUPITER is hosted by the Jülich Supercomputer Centre (JSC), close to ECMWF’s offices in Bonn, Germany, and is already number 4 in the TOP500 list of most powerful supercomputers globally.
From the initial phase, while JUPITER was still being deployed, 15 successful projects have operated on the JUPITER development system JEDI (JUPITER Exascale Development Instrument). This module has consistently ranked as number 1 in the Green500 list, meaning it is one of the most energy-efficient in the world, and it ranks 259 in the TOP500 most powerful supercomputers.
“We are very happy to have this opportunity to pioneer the use of this incredible machine. New machines are both exciting and a challenge, but we have experience with different EuroHPC sites over the past two years in Destination Earth, as well as accessing machines in the USA and Japan, and we’ve already managed to run the first numerical weather prediction simulations with both our Integrated Forecasting System (IFS) and Artificial Intelligence Forecasting System (AIFS) on JUPITER. We are happy to contribute to the efforts of our Member States and the wider community to push the limits of NWP,” said Nils Wedi, Digital Technology Lead for Destination Earth at ECMWF, leading the project at the Centre.
Peter Düben, Head of Earth System Modelling at ECMWF, highlighted the importance of the JUPITER exascale for advancing weather and climate modelling: “We are currently witnessing significant changes in the field of Earth system modelling as machine learning is changing the way numerical weather forecasting is done. It is, therefore, essential that machines like JUPITER provide Europe with sufficient compute power to develop large machine learning models such as ECMWF’s AIFS to secure Europe’s world-leading position in weather and climate modelling.”
Extreme scale computing for extreme weather prediction
This computing power, unprecedented in Europe, will allow ECMWF to perform global km-scale simulations matching the resolution of the latest generation of EUMETSAT’s Meteosat Third Generation-Imager (MTG-I) and the Meteosat Third Generation Sounder (MTG-S).
The simulations of “JUPITER meets Europa – Extreme ExaScale Global Weather Forecasting for a changing climate” will provide the opportunity to run for the first time the full GPU port of the IFS model with invaluable insights to improve the scalability of the model components at extreme scales. The proposal submitted to the JUPITER exascale supercomputer meets the World Meteorological Organization (WMO) scientific advisory panel recommendations for advancing km-scale modelling and the exploitation of observations in addressing systematic errors, as well as advancing the ability to predict weather in a changing climate, in particular for extreme events.
Destination Earth, Lighthouse project at JUPITER
The simulations closely relate to the current and future simulation capabilities in DestinE, the ambitious initiative led by the EU Commission’s DG CNECT to develop a highly accurate digital replica of the Earth system. In turn, the developments already deployed by ECMWF in the context of DestinE for big data handling and adaptation measures for the models should benefit the project.
“We are very happy that DestinE has been selected as one of the Lighthouse projects selected by our partners in EuroHPC for the JUPITER supercomputer simulations. Our experience in deploying our codes on other EuroHPC machines, such as LUMI in Finland, MareNostrum5 in Spain and Leonardo in Italy will help us exploit the fastest supercomputer in Europe. This impressive computing power will contribute to our work in pushing km-scale Earth system simulations and integrating AI/ML-driven components to refine the digital twins and the Digital Twin Engine,” said Irina Sandu, Director for Destination Earth at ECMWF.
The Climate Change Adaptation Digital Twin (Climate DT) of DestinE has recently been shortlisted for the prestigious Gordon Bell Prize for Climate Modelling of the Association for Computing Machinery (ACM) after a submission from a team including ECMWF, the Max Planck Institute for Meteorology, CSC, the Alfred Wegener Institute, the German Climate Computing Center (DKRZ), and the Barcelona Supercomputing Center (BSC), supported by the two EuroHPC hosting sites, CSC (LUMI) and BSC (MareNostrum 5). The Climate DT received the HPCwire Readers’ Choice Award for the “Top HPC-Enabled Scientific Achievement” in 2024, and the DestinE initiative was recognised for the “Best Use of HPC in Physical Sciences.”
Setting the scene for full exascale in Europe
The JUPITER Research and Early Access Program (JUREAP) provides the framework for testing and preparing the hardware and applications of the first European exascale machine. The GCS Exascale Pioneer Call was issued as a part of the JUREAP, which has three main phases:
- The Scalability and Performance Evaluation Phase
- The Porting and Optimizing Phase
- The Outstanding Research Phase
The selected projects are awarded large-scale computer resources on JUPITER after the full launch and will be able to use a significant share of the available resources during the deployment phase, contributing to preparations for the full launch of JUPITER. The preparation period takes place in the second phase of JUREAP.
The projects selected alongside ECMWF’s for the JUREAP calls in this initial phase range from other Earth-system simulations to hydrodynamics, artificial intelligence foundation models and other physics-related simulations. Notably, a companion project by Dr Daniel Klocke (Max Planck Institute for Meteorology, MPI) on “Exascale enabled Scale and Process Interactions in the Earth System” is also among the successful projects, with the ICON (Icosahedral Nonhydrostatic) model of the German weather service Deutscher Wetterdienst (DWD) and MPI also deployed in Destination Earth in the Climate Digital Twin alongside ECMWF’s IFS.
Further reading
More information about the JUPITER launch is available on the EuroHPC website.