Changes in ice-season characteristics of a European Arctic lake from 1964 to 2008

• Published in: Climatic Change
• Main Authors: Lei, R, Lepparanta, M, Cheng, B, Heil, P, Li, Z
• Format: Article in Journal/Newspaper
• Language: English
• Published: Kluwer Academic Publ 2012
• Subjects: Earth Sciences; Physical Geography and Environmental Geoscience; Glaciology; Arctic; Arctic Lake; Climate change; North Atlantic; North Atlantic oscillation
• Online Access: https://doi.org/10.1007/s10584-012-0489-2; http://ecite.utas.edu.au/80533

The long-term ice record (from 1964 to 2008) of an Arctic lake in northern Europe (Lake Kilpisjrvi) reveals the response of lake ice to climate change at local and regional scales. Average freeze-up and ice breakup occurred on 9 November and 19 June, respectively. The freeze-up has been significantly delayed at a rate of 2.3 d per decade from 1964 onward ( P < 0.05). No significant change has taken place in ice breakup. Annual average ice thickness has become smaller since the mid-1980s ( P < 0.05). Air temperature during the early ice season significantly affected the ice thickness. The freeze-up date exhibits the highest correlation with the 2-month average daily minimum air temperature centered at the end of October, while the ice breakup date exhibits the highest correlation with the 2-month average daily maximal air temperature centered in mid May. A 1C increase in the surface air temperature corresponds to a freeze-up later by 3.4days and an ice breakup earlier by 3.6days. Snow cover is a critical factor in lake-ice climatology. For cumulative November to March precipitation of less than 0.13m, the insulating effect of the snow dominated, while higher rates of precipitation favored thicker ice due to the formation of snow ice. Variations in ice records of Lake Kilpisjrvi can serve as an indicator of climate variations across the northern Europe. The North Atlantic Oscillation (NAO) does not significantly affect the ice season there, although both the local air temperatures and winter precipitation contain a strong NAO signal.