On 12 May 2026, a group of thirteen HErZ early career scientists (ECSs) visited the ECMWF in Bonn for a full day of scientific exchange. The event was jointly organised by the ECS representatives Moritz Schnelke and Stefano Franzoni with the support of the coordinator Audine Laurian (HErZ), and by Tobias Necker and Michael Maier-Gerber (ECMWF).

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 (Tobias Becker), the 4D-Var data assimilation system and its ongoing development towards a coupled Earth System framework, along with AI integrations and AI-DOP (Peter Weston), reanalysis production (Paul Poli), and AI-based forecasting with the AIFS system and the ANEMOI framework (Mariana Claire). A talk on career opportunities at ECMWF and related organisations was also part of the program (Niels Lohmann). The session closed with shorter contributions from ECMWF-DWD Fellows on subjects ranging from cloud evaluation using EarthCARE data (Kim Andreas Weiss) to soil moisture retrieval (Eleni Kalogeraki), land data assimilation for river discharge (Francesca Covella), Arctic clouds in IFS (Luise Schulte), and impact of aerosol (Paolo Andreozzi).

In the afternoon, after an overview of HErZ, the 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.

Coffee breaks and lunch provided further opportunities to chat with ECMWF staff in a more relaxed setting, which was useful for exchanging ideas and making contacts.

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. The ECSs thank ECMWF, and in particular Tobias Necker and Michael Maier-Gerber, for hosting them and for organising a well-structured and exciting programme.

The programme of the event is available here.

Participants at ECMWF. Photo: Tobias Necker (ECMWF)