 Troll is operated by the Norwegian Polar Institute and also features facilities for the Norwegian Meteorological Institute and the Norwegian Institute for Air Research.Contrary to most other research stations on the continent, Troll is constructed on the snow-free slope of solid rock breaking through the ice sheet at Jutulsessen, located above mean sea level.The station opened as a summer-only station in 1990 and was taken into use as an all-year station in 2005.