Lessons learnt from comparing global and regional models

In the last 10 years, regional and global models have evolved importantly. Regional models have extended their boundaries beyond the continental slope, while global models have increased resolution to handle the turbulent scales. In the process, numerical methods and parametrizations have converged. Because of this and the open boundary conditions issue, some may be tempted to question the relevancy of the regional approach as computational costs keep decreasing. In this presentation we will show with some examples that the regional approach, particularly with new-generation models, is still very relevant and may have lead us to produce regional solutions of unprecedented quality. However, we will also discuss some of the drawbacks of our system and see how it may evolve in the future.