There is no single geographical definition of the extent of the Arctic, and even less so of the European Arctic. There is also no political agreement on the definition of the concept. Iceland, Svalbard archipelago, Franz Joseph Land, and Novaja Zernlja, Scandinavia and Finland north of the Arctic Circle, Murmansk oblast and northern Arkangelsk oblast, northern Karelia, and Nenets east to Yamal, the seas of these land areas as well as the international waters between them. The main geophysical characteristics of the Arctic are low temperatures with pronounced seasonal variations in climate, including a large variation in the solar radiation between the long night of winter and the long day of summer, and the extended periods of ice and snow cover. On land the temperatures vary greatly through the seasons, and permafrost strongly influences soil formation, vegetation structure, and hydrological processes.
Glaciers are predominant only on the High Arctic islands.
Arctic sea temperatures are more stable than land temperatures throughout the year. Sea ice development strongly influences the marine ecosystem dynamics. The Barents and Kara Seas are among the largest shallow continental shelf seas in the world. Due to influxes of warm air and water from the south, these areas are generally the mildest and most humid parts of the Arctic. The geophysical characteristics of the arctic seas also contribute to large-scale deep water formation east of Iceland and Greenland.