A long-term Arctic snow depth record from Abisko, northern Sweden, 1913–2004

Abstract

A newly digitized record of snow depth from the Abisko Scientifi c Research Station in northern Sweden covers the period 1913-present. Mean snow depths were taken from paper records of measurements made on a profi le comprising 10 permanent stakes. This long-term record yields snow depths consistent with two other shorter term Abisko records: measurements made at another 10-stake profi le (1974-present) and at a single stake (1956-present). The measurement interval is variable, ranging from daily to monthly, and there are no data for about half of the winter months in the period 1930-1956. To fi ll the gaps, we use a simple snowpack model driven by concurrent temperature and precipitation measurements at Abisko. Model snow depths are similar to observed; differences between the two records are comparable to those between profi le and single stake measurements. For both model and observed snow depth records, the most statistically signifi cant trend is in winter mean snow depths, amounting to an increase of about 2 cm or 5 % of the mean per decade over the whole measurement period, and 10 % per decade since the 1930-40s, but all seasonal means of snow depth show positive trends on the longest timescales. However, the start, end, and length of the snow season do not show any statistically signifi cant long-term trends. Finally, the relation between the Arctic Oscillation index and Abisko temperature, precipitation and snow depth is positive and highly signifi cant, with the best correlations for winter.

Assessment of Biological and Environmental Phenology at a Landscape Level from 30 Years of Fixed-Date Repeat Photography in Northern Sweden

“…Such decreases in snow depth coupled with the earlier spring thaw but stable on-set dates, is consistent with a springtime snow albedo feedback kicking in at lower elevations. Overall, these declines in length of snow cover at both low and high elevation contradict projected increases in long-term snow depth suggested by Kohler et al (2006), whilst supporting data showing rapid decreases in snow depth since the 1980s (Callaghan et al 2010).…”

“…Ice cover on Lake Torneträsk was reduced by 7.5 weeks over the period, whilst low and high elevation snow cover were reduced by 5.1 and 3.1 weeks, respectively, providing evidence that contradicts other analyses of short-and long-term increases in arctic snowfall (Pettorelli et al 2005;Kohler et al 2006). Changes in birch phenology were smaller with leaf cover occurring 1.6 weeks earlier for the period.…”

The thermal state of permafrost in the nordic area during the international polar year 2007–2009

“…Snow depth has been recorded since 1913 at the Abisko Scientific Research Station, which is situated 6 km west of Storflaket, and 2 km west of Kursflaket. The long-term trend since 1913 shows an increase in snow depth during the past 100 years (Kohler et al, 2006), but no change in the date of snow cover onset or end. However, during the past decade a decreasing trend in snow depth has been observed.…”

Changes in Tree Growth, Biomass and Vegetation Over a 13-Year Period in the Swedish Sub-Arctic

“…Climate change is accelerating at Abisko and the mean annual temperature recorded at the beginning of the 21st century was 0.7°C (Kohler et al 2006) which is 2.5°C greater than in the beginning of the twentieth century (Callaghan et al 2010). The mean annual precipitation, measured at Abisko Scientific Research Station (ANS), is *310 mm for the period 1913-2000 (Kohler et al 2006). The mean annual precipitation on the northern side of the lake could, however, be about twice as high as recorded at ANS (Sonesson and Hoogsteger 1983).…”