GridTools: A framework for portable weather and climate applications

Abstract 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.