With the creation of the EuroHPC Joint Undertaking (JU), the development of extreme-scale computing systems in Europe is picking up steam. Five peta-scale and three pre-exascale systems will be deployed in 2020-2021 timeframe, and it is planned that two exa-scale systems will be introduced by 2023. Additionally, several national systems will be deployed in the UK, Germany and Switzerland during the same timeframe. Moreover, efforts are underway to allow several of these supercomputing systems to operate as a common, federated infrastructure, offering data and compute services in a transparent way.
From an architectural point of view, it is clear that during the early 2020s most affordable extreme-scale supercomputing systems will be GPU accelerated with offerings from multiple vendors. At the same time, there are many open questions on how the programming models will evolve in the coming decade. There are several European initiatives that are addressing this challenged via introduction of domain specific languages. Some of the most advanced in the weather and climate domain will be discussed.