The MAP Service presents selected historical ice chart of sea-ice observations in the Arctic region between 30ºW and 70ºE based on ACSYS HISTORICAL ICE CHART ARCHIVE, (1553 – 2002)1. The earliest charts shown dates from 1553, and the most recent from December 2002. These historical data have been supplied with ice charts showing 10 years mean sea-ice extents based on observation from 1969 to 2008, and 30 years mean sea-ice extents from 1979 to 2008. In addition, the sea-ice extent is shown for March and September 2008 which generally describe maximum and minimum extent in the Barents Sea. As can be shown in our portal, there has been a tremendous change is sea-ice extents during the resent years. The early sea-ice observations were recorded by vessels sailing to the Arctic to explore or to hunt whales and seals. Over the centuries, technological advances and commercial opportunities in the Arctic led to more frequent and regular sea-ice observations, with associated increasing accuracy. As sailing ships gave way to steam powered vessels, and with the advent of aircraft and satellites, regular mapping of sea ice conditions became an organized activity. From 1967 onwards, hand drawn weekly charts were produced, showing not only an ice edge, but also concentrations of sea ice within the ice pack. Since July 1997, improved technology allowed daily production of digital sea ice maps on workdays. In an effort spanning many years, early observations from ship logbooks and other records were collected, translated as necessary, and plotted as hand-drawn maps. For more recent years, sea ice charts from various organized sources were collected. The totals of over six thousand charts are available in the ACSYS HISTORICAL ICE CHART ARCHIVE, (1553 – 2002).
The BarentsPortal financed in 2009 a project with goals to do a aggregation of data from ACSYS with a updating of the sea-ice extent till 2008. Please go to the MAP Service to find the visual presentation under section Oceanography.