A recent article led by Stein Sandven from the Nansen Center reviews the developments in sea-ice remote sensing over the last decades, benefitting operational ice services and polar climate science.

Satellites with different types of instruments onboard watch our poles continuously. Using these to monitor the sea ice in polar regions provides unique climate data records. From 1972 regular time series of ice concentration and ice extent in both the Arctic and Antarctic exist thanks to passive microwave data. The time series shows that the ice extent has declined in the Arctic, but not in Antarctica. Radar altimeter data provide monthly mean estimates of ice thickness for the winter months since 1993, showing significant thinning from the 1990’s to the 2010’s.

Sea-ice data from satellites are also important for the operational ice services providing ice charts and ice forecasts for ship traffic in the polar regions. The information is also important for other users such as fisheries, marine ecosystems, offshore operations, and maritime authorities.

The article by Stein Sandven and colleagues in Germany, France, and the USA, outlines in detail  remote sensing methods that were developed to derive sea-ice variables from the satellite sensors. The article is useful for people interested in sea-ice retrieval algorithms as well as in studies of sea-ice variability and trends in both polar regions. The authors also give some perspectives of what new satellites will provide of sea-ice data in the coming years.