Sea ice extent and ice surface temperatures in the Arctic
Sea ice hysteresis
Arctic Sea Ice extent hysteresis
The Arctic Sea Ice Extent (SIE) and the associated Ice Surface Temperature (IST) are highly correlated variables. The SIE increases during the Arctic cooling period and decreases during warming period. This interaction was for many years a rather stabile hysteresis system, where the SIE assumes 2 states for the same mean temperature, depending on whether the IST is increasing (in spring) or decresing (in autumn). Since 2007, where the largest loss of multy-year ice in recent time occurred, the earlier rather predictable hysteresis loop has changed significantly.
The SIE-IST hysteresis is illustrated in the animated figure, where monthly pairs of SIE and IST since 1982 are plotted.
The sea ice extent data are compiled from a Sea Ice Concentration (SIC) Climate Data Record (CDR, 1979-2015) and an Interim CDR (ICDR, since 2015). The SIE is determined by the area where SIC is greater than 30%. The data are available at the Ocean and Sea Ice Satellite Application Facility (OSISAF), as products OSI-450 and OSI-430, respectively.
The corresponding Ice Surface Temperature data are compiled from the Copernicus Marine Environment Monitoring Service Arctic Level-4 IST product (CMEMS IST).