Weather forecasts and climate projections are of tremendous importance for economical and societal reasons. Software implementing weather and climate models is complex to develop and hard to maintain, and requires a large range of different competencies, ranging from environmental sciences, numerical methods, to low level programming. In order to manage this complexity we developed GridTools, a set of software libraries targeted at weather and climate model developers. By separating the model description (front-end) from its efficient implementation on the target platform (back-end), GridTools allows the implementation of performance-portable simulations on a variety of platforms, such as multicore and GPU-accelerated systems. We discuss the application of GridTools to the regional weather and climate model COSMO and show performance results on simple benchmarks as well as on COSMO.
