Re-calibration of Arctic sea ice extent datasets using Arctic surface air temperature records
Abstract: A new seasonal and annual dataset describing Arctic sea ice extents for 1901-2015 was constructed by individually re-calibrating sea ice data sources from the three Arctic regions (North American, Nordic and Siberian) using the corresponding surface air temperature trends for the pre-satellite era (1901-1978), so that the strong relationship between seasonal sea ice extent and surface air temperature which has been observed for the satellite era (1979-present) also applies to the pre-satellite era. According to this new dataset, the recent period of Arctic sea ice retreat since the 1970s followed a period of sea ice growth since the mid-1940s, which in turn followed a period of sea ice retreat since the 1910s. Arctic sea ice is a key component of the Arctic hydrological cycle both through its freshwater storage role, and its influence on oceanic and atmospheric circulation. Therefore, these new insights have significance for our understanding of Arctic hydrology.