Here Russian historical sea ice data, going back to the beginning of the 20th century, are presented. The database was created in Arctic and Antarctic Research Institute, St. Petersburg, Russia. Table contains data description, information on the data spatial and temporal coverage, as well as links to data and illustrations.

The data archive includes:
1. Annual ice area for North Europe Basin
2. Annual ice area for the 77% of the Arctic Ocean (missing Canadian Arctic, the Beaufort and Chukchi Sea)
3. Monthly (August) ice area for Siberian Arctic waters
See the location of the boundaries of the Arctic Ocean seas on the map.

Analysis of observational data revealed four stages in sea ice cover development during the 20th century :
1) Until 1918, the processes of sea ice cover expansion with a mean annual rate of +159 thousand km2/decade predominated.
2) From 1918, the ice area in the North-European basin and in the other regions of the Arctic Ocean began to decrease.
3) A significant ice concentration increase from 1946 towards the subsequent two decades occurred in the Kara Sea and also in the Laptev Sea. On the contrary, in the East-Siberian and the Chukchi Seas, the ice concentration decreased from the beginning to the end of this stage.
4) Since the end of the 1960s and especially from the early 1990s quite intense ice area decrease started in the entire Arctic Ocean. Thus, the East Greenland ice belt in August reduced from 539 to 278 thousand km2 from 1989 to 1990 and the Barents Sea ice from 222 to 97 thousand km2. The ice area decreased from 456 to 79 in the East-Siberian Sea and from 393 to 109 thousand km2 in the Laptev Sea.

The detailed analysis of variations of Arctic sea ice extent in the 20th century from dataset based on available Russian observations, as well as analysis of regional features in sea ice extent in the Arctic Ocean from Russian data can be found in scientific reports. <br><br>

References