Cruise CIAAN (Constraining the Impact of Arctic Amplification in the Nordic Sea) was a 16 day interdisciplinary and multi-themed research cruise that took place on board the R.V. Celtic Explorer in August/September 2020, The cruise took a holistic approach to transform our understanding of how the signature of climate change is recorded in the Nordic Seas (e.g. temperature, salinity, and the carbonate system (CTD)) and transferred into geologic archives (Multi- and Gravity Cores) via foraminifera. The work program was multinational and facilitated trans-European co-operation through collaboration between an Irish and three leading European Institutes. It brought together researchers from two disciplines at the National University of Ireland Galway (NUIG) - Geography and Earth and Ocean Sciences, with researchers also from the University of Southampton, MARUM Research Facility in Germany and the Bjerknes Centre for Climate Research in Norway. During the survey 13 CTD , 11 Multinet Vertical and 7 Multinet Oblique casts were successfully carried out. 5 Multicores, 2 Box Corer and 12 gravity core casts were also conducted. 3 Argo floats were also deployed. The research linked to the project 'Constraining the Impact of Arctic Amplification in the Nordic Sea (CIAAN)' will support global efforts to improve our understanding of Essential Climate Variables (ECVs) in the Nordic Seas, which is a key region for the formation of North Atlantic Deepwater and the uptake of atmospheric carbon dioxide (pCO2). Specifically, CIAAN aims to define a more comprehensive description of biogeochemical processes in the Nordic Seas and will provide transformative insights into how ECVs are recorded in geologic archives to improve the “long-term monitoring, surveying and modelling to understand the processes and feedback mechanisms between the ocean and atmospheric systems” (Joint Programming Initiative Healthy and Productive Seas and Oceans).