Models 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. Data assimilationData assimilation are methods that combine measurements of the climate and environment, such as temperature and wind, with models. Through this process, more accurate descriptions of a current state are produced, which in turn will form the basis for more secure forecasts. Artificial intelligenceComputers can be programmed to analyze and recognize patterns in large amounts of data. This is called machine learning, an important field within artificial intelligence. In research, this is used, among other things, for the analysis of large amounts of data and for the forecasting of changes in the environment or climate. Through the use of artificial intelligence, we can prepare far better forecasts than before, and present good and secure analysis and decision-making bases. Ocean modelsOne of our key areas of expertise is the development of operational ocean models linked with ecosystem models. The models use advanced data assimilation techniques and deliver continuous information about the state of the sea to, among other things, central service providers in Copernicus, Europe's major Earth observation program for climate and environmental monitoring. Sea-ice modelsA ground-breaking work at the Nansen Center is the development of a unique sea-ice model, which reproduces processes such as the formation of leads and ridges in the ice. The model is used both in operational services and for more traditional research. Climate modelsClimate models are used to calculate developments in climate, where natural or man-made influencing factors such as solar radiation, volcanoes, greenhouse gases, and particle emissions can be included in the calculation basis. Over many years, we have actively contributed to the development of internationally recognized models, which provide more precise projections, i.e., forecasts, of climate change. The models can also be used to increase knowledge about past climates.