Copernicus Marine Service – a treasure trove of information Through the EU/ESA’s major Earth observation program Copernicus, the Sentinel satellites collect information about various conditions in the sea, the atmosphere, and on land, using various radar and camera systems. The program is a very important investment in increased understanding of nature, climate change, and our external environment. Copernicus Marine Service, which is the marine part of the programme, has the main task of producing key indicators for the sea such as temperature, salinity, ocean currents, sea level, and sea-ice extent. The service provides the most up-to-date and most easily accessible marine information and contributes to the development of knowledge about the state of the ocean in the past, present, and future. Through observations of ocean conditions, and simulations carried out using advanced circulation models, basic and quality-assured information is presented that everyone can use – completely free of charge. The products are important for weather forecasting, for safeguarding maritime safety and transport, monitoring oil spills and water quality, and for monitoring changes in the environment and climate in the polar regions. The Nansen Center leads the Arctic – Monitoring Forecasting Centre, one of the marine services that delivers ocean forecasts and sea-ice forecasts for the coming 10 days. The forecasts are produced using models and assimilation techniques, which incorporate daily observations of ocean conditions, and provide a significant improvement in the level of precision of the forecasts. Well-functioning marine services are relevant to several sectors such as energy, fisheries, tourism, and transport. In 2022, the Nansen Center was awarded funds through the European Commission’s Horizon Europe programme, to improve existing products and develop new services for the Copernicus program. In the ACCIBERG project, research will provide better forecasts for sea ice and new forecasts of icebergs in the Arctic Ocean, which will be more accurate than what is available in the current service. The project is led by Laurent Bertino. In the NECCTON project, new products are being developed for the Copernicus Marine Service, which will contribute to new knowledge about biological diversity in the sea and to a better management of marine ecosystems. The project work at the Nansen Center is led by Annette Samuelsen. We are proud to be able to contribute to improving existing and developing new products for the benefit of society. Optimisation of forecasts Through research and development of better calculation methods, the forecasts are becoming increasingly precise. The marine ecosystem products have been updated with a new model reanalysis (ECOSMO-II) which extends back to 1991. In addition to physical ocean variables, this “look back” at past conditions also includes products for the concentration of chlorophyll, oxygen, nitrate, and other nutrients. With such information available, users can compare forecasts for the coming week with what has been the normal state for the past decades.