Retrospective reconstruction of 40 years of atmospheric fields in Northern Europe using the WeatherGenerator foundation model

Within the WeatherGenerator project, the Norwegian Meteorological Institute (MET Norway) is applying the project’s foundation model to reconstruct several decades -ideally the most recent 40 years- of atmospheric fields over Scandinavia. The primary objective of this work is to assess the potential of the WeatherGenerator framework for climate monitoring applications.

WeatherGenerator is a pan-European initiative that combines state-of-the-art machine-learning architectures with high-performance computing to develop an open, kilometer-scale foundation model of the coupled Earth system. The project is organized into four thematic areas; the application presented here is one of twenty-two applications developed by project partners within Theme 3.

The reconstructed datasets include near-surface atmospheric variables as well as variables at multiple pressure levels. The approach integrates heterogeneous data sources -ranging from in situ observations and reanalysis products to numerical model output- leveraging the foundation model to generate consistent, high-resolution fields suitable for climate and weather monitoring. The target spatial resolution is 1 km, achieved through data fusion techniques and a task-specific tail network trained to produce gridded analyses at this scale. Multiple temporal resolutions are explored, including hourly data and daily to monthly aggregations.

This contribution represents MET Norway’s first presentation of WeatherGenerator-related results at a scientific conference. The focus is therefore on preliminary results, outlining the overall methodological framework and demonstrating the potential of these novel approaches for high-resolution climate monitoring.

Note: The WeatherGenerator project (grant agreement No101187947) is funded by the European Union. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union or the Commission. Neither the European Union nor the granting authority can be held responsible for them.