Sustainability and Climate Risks
Research UnitSustainability and Climate Risks
FNK at first global km-scale hackathon
28 May 2025
Photo: express.converia.de
From May 12-16 2025 the first global km-scale hackathon organised by the World Meteorological Organization's Digital Earths Lighthouse Activity took place. It was located at 10 nodes around the world, from Buenos Aires to Tokyo, and also Hamburg. The hackathon aimed to allow participants to work with the latest km-scale global climate models developed around the world. These next-generation models are run at spatial resolutions of 5km or even less, which presents a step-change compared to the last generation of CMIP6 models, which ran at around 100km.
The increased resolution of these models allows to resolve processes, such as deep convection, which have to be approximated empirically in coarser models, and to better represent local details, which is particularly important for extremes. At the same time, the vast amounts of data produced by these models are hard to organise, access, and process. Addressing these challenges and investigating the prospects of km-scale models was the main aim of the first global hackathon.
Hartmut Borth, Lukas Brunner, and Josipa Županić joined the Hamburg node for FNK.
Lukas organised a science team on the global representation of local extremes (hk25-LocExt), which was joined by about 10 people in Hamburg and 4 online participants. LocExt aimed to investigate the added value of high-resolution output for the spatial representation of climate extremes and to understand potential differences between models.
Josipa joined the DestinE group, curious about a recently created family of simulations: the nudged storyline runs. These runs are useful for looking at extreme events that happened during the nudged period (2017–2023) and for exploring how such events might change in a world that’s 2 degrees warmer or in a world without climate change.
Others in the DestinE group were also curious about the storyline data and teamed up to look into different topics, e.g., the 2022 floods in Pakistan and how sea ice is represented in the Weddell Sea, while Josipa focused on July 2022 heatwaves. She also joined a few side events, including visits to the HPC Levante at DKRZ and the wind tunnel at Geomatikum.
