The latest cycle of the Coupled Model Intercomparison Project (CMIP7) is about to start producing simulations in support of the IPCC's Seventh Assessment Report (AR7). Concurrently, CORDEX is in the midst of generating the CORDEX-CMIP6 ensemble, with several regional communities still underrepresented in this dataset. Recent efforts in developing protocols and technical documentation for CORDEX-CMIP6 have laid a foundation for the upcoming CORDEX-CMIP7. However, integrating the advancements in modelling strategies from both CMIP and CORDEX will be essential.

The primary task for this Task Force (TF) is to evaluate whether CORDEX can and should adopt CMIP7 forcing in time to contribute to the next IPCC AR7. Balancing the innovation and demand for CMIP7-forced data with the complexities of releasing two products—CORDEX-CMIP6 and CORDEX-CMIP7—simultaneously is critical. This dual effort could potentially detract from the completeness of the CORDEX-CMIP6 ensemble. To align with the AR7 timeline, the CORDEX-CMIP7 protocols and technical documentation should be finalized by the time the first CMIP7 models become available for downscaling, expected in about one year.

Regardless of the timeline, CORDEX-CMIP7 will inevitably take shape in the coming years, requiring the community to be adequately prepared. This TF will explore the necessary actions and steps to ensure a smooth transition to a CMIP7-driven CORDEX ensemble. Achieving this will require collaboration among diverse experts and consultation with the broader CORDEX community. Ultimately, the TF should evolve into a dedicated working group tasked with
developing the required actions/steps and maintaining the documentation and infrastructure.

The diversity of CORDEX models has increased and, for the next CMIP cycle, the experimental  design must account for Regional Climate Models (RCMs) with varied coupled components, a resolution increase to convection-permitting, few-kilometer scales, and the extensive use of  Empirical Statistical Downscaling and Emulators benefiting from new Machine Learning techniques. Therefore, close coordination with other ongoing CORDEX TFs will be necessary.
Additionally, addressing the long-standing challenge of ensuring that forcing datasets are fully consistent with the driving CMIP Global Climate Models should be a priority for CORDEX-CMIP7.

Jesús Fernández jesus.fernandez@ifca.unican.es