In order to produce reliable results in climate and environmental research, we develop advanced methods and tools, including various model systems. These models are large, advanced computer programs, which, based on measurements and known relationships (physical, chemical, and biological), are used to calculate what the state of the earth system is; diagnosis – or will be; forecast. We have models for calculating conditions in the ocean, sea ice, atmosphere, and climate. We develop our own models and also contribute to model development in larger collaborations. Our researchers have specialist expertise in the use of data assimilation and artificial intelligence to improve models – and to prepare the forecasts that are produced through the models.