A look at the date of snowmelt and correlations with the Arctic Oscillation

作者：Foster J L^*; Cohen J; Robinson D A; Estilow T W

来源：Annals of Glaciology, 2013, 54(62): 196-204.

DOI：10.3189/2013AoG62A090

Spring snow cover across Arctic lands has, on average, retreated similar to 5 days earlier since the late 1980s compared to the previous similar to 20 years. However, it appears that since about the late 1980s the date the snowline first retreats north during the spring has changed only slightly: in the last 20 years snow has not been disappearing significantly earlier. Snowmelt changes observed since the late 1980s have been step-like, unlike the more continuous downward trend seen in Arctic sea-ice extent. At 70 degrees N, several longitudinal segments (of 10 degrees) show significant (negative) trends, while only two longitudinal segments at 60 degrees N show significant trends, one positive and one negative. These variations appear to be related to variations in the Arctic Oscillation (AO). When the springtime AO is strongly positive, snow melts earlier. When it is strongly negative, snow disappears later in the spring. The winter AO is less straightforward. At higher latitudes (70 degrees N), a positive AO during the winter months is correlated with later snowmelt, but at lower latitudes (50 degrees N and 60 degrees N) a positive wintertime AO is correlated with earlier snowmelt. If the AO during the winter months is negative, the reverse is true. Similar stepwise changes (since the late 1980s) have been noted in sea surface temperatures and in phytoplankton abundance as well as in snow cover.

• 出版日期2013