ASCOS was the latest in a series of expeditions to the central Arc-tic Ocean on the Swedish icebreaker Oden to study Arctic summer clouds: the International Arctic Ocean Expedition in 1991 (IAOE-91, here Oden became the first non-nuclear powered vessel to reach the North Pole) and the Arctic Ocean Experiments in 1996 (AOE-96) and 2001 (AOE-2001). These atmospheric studies in the central Arctic Ocean, north of 80 N, started with a small group and limited resources in 1991 and has since grown to a large international multidisciplinary consortium. Below please find the database of ASCOS together with the links to the data gathered in AOE-96 and AOE-2001. The data volume from IAOE-91 is less extensive and will given time be made available at this location.