Influence of Meteorological Elements on Changes in Active‐Layer Thickness in the Bellsund region, Svalbard

Abstract

ABSTRACTMeasurements of active‐layer thickness (ALT) at seven locations on Calypsostranda, Svalbard (CALM Site P1), over 1986–2009, are used to estimate the influence of cloudiness, precipitation, air temperature, the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO). Between 1986 and 2002, ALT amounted to 118 ± 14 cm and did not show any significant trend. During 2002–06, ALT increased rapidly (12.6 cm yr‐1) to a maximum of ~ 174 cm in 2006 and 2007. In 2008 and 2009, ALT decreased. No statistically significant correlations were determined between ALT and monthly precipitation and cloudiness at Barentsburg, Hornsund and Svalbard Airport stations. There were, however, very strong and highly significant (p < 0.001) relationships with air temperatures in May and June (the strongest association being with Svalbard Airport). The influence of air temperature in May and June on ALT is indirect; it regulates the time of the melt of snow cover, which determines the duration of the ground‐warming period. Using statistical relationships between ALT and air temperature at Svalbard Airport, the time series of ALT at Calypsostranda is reconstructed from 1911 to 2010. It was also found that the AO and the NAO did not significantly affect ALT and air temperature on western Spitsbergen. Copyright © 2013 John Wiley & Sons, Ltd.