GC5-LFRic: Developing the next Met Office coupled atmosphere-ocean model with a cubed-sphere atmosphere grid.

The Met Office uses its global coupled atmosphere-ocean model for predictions on timescales from days to centuries as part of its seamless prediction framework. The atmospheric component of the coupled system is the Unified Model on a latitude-longitude grid. With ever increasing resolution and significant changes to high performance computing such as new processor types and increased parallelisation, a fundamentally new atmosphere model is needed to meet future requirements. A major effort is underway to develop a new version of the coupled model using the GungHo dynamical core on a cube-sphere grid with atmospheric physics from the existing unified model. This is coupled to the NEMO ocean model and SI3 sea-ice model on a tripolar grid. We will show results from the latest prototype models for numerical weather prediction and climate simulations. We will also discuss the ongoing work and challenges to make these systems operational at the Met Office.