HErZ Meets ECMWF in Bonn

On 12 May 2026, a group of HErZ early career scientists (ECSs) and master students involved in HErZ-related topics travelled to ECMWF in Bonn for a full day of scientific exchange. The visit brought together eleven HErZ ECSs and two master students with researchers and staff from one of the world’s leading numerical weather prediction centres. The event was jointly organised by project coordinator Audine Laurian on behalf of the HErZ ECSs, and by Tobias Necker and Michael Maier-Gerber on the ECMWF side. The evening before the visit, the HErZ ECSs took the opportunity to share the dinner together, which was a good chance to catch up more informally and exchange news from the various groups. The morning session featured presentations by ECMWF scientists covering the main areas of the centre's research.

Topics included physical parametrizations in the IFS model, the 4D-Var data assimilation system and its ongoing development towards a coupled Earth System framework, along with AI integrations and AI-DOP, reanalysis production, and AI-based forecasting with the AIFS system and the ANEMOI framework. A talk on career opportunities at ECMWF and related organisations was also included. The session closed with shorter contributions from ECMWF-DWD Fellows on subjects ranging from cloud evaluation using EarthCARE data to soil moisture retrieval, land data assimilation for river discharge,  Arctic clouds in IFS, and impact of aerosol. Coffee breaks and lunch provided further opportunity to chat with ECMWF staff in a less formal setting, which was a useful complement to the presentations for exchanging ideas and making contacts.

In the afternoon, after an overview of the HErZ project presented by Audine Laurian, HErZ participants presented their own research to ECMWF staff. The programme covered a range of topics across cloud physics, data assimilation, AI methods, and large-scale dynamics. The visit offered a productive mix of scientific presentations, informal discussions, and networking. It gave HErZ ECSs direct contact with the research environment at ECMWF, contributed to raising the visibility of the HErZ network, and provided a useful occasion for the community to spend time together. We thank ECMWF organizers for hosting us and for organising a well-structured programme.