New Study: Swiss Alps Cooling Since 2000
A new study titled Snow variability in the Swiss Alps 1864–2009 appearing in the Journal of Climatology by Simon Scherrer et al. shows a temperature trend reversal has been taking place in the Swiss Alps since 2000.
The paper looks at nine Swiss Alpine snow series that cover different altitudes (450–1860 m asl) and go back more than 100 years. In addition the authors analyzed data from 71 stations covering the last 50–80 years to get a more complete picture of Swiss Alpine snow variability.
They analysed data for trend and variability for:
- New snow sums (NSS)
- Maximum new snow (MAXNS)
- Days with snowfall (DWSF)
According to their abstract (my emphasis):
Our results reveal large decadal variability with phases of low and high values for NSS, DWSF and DWSP. For most stations NSS, DWSF and DWSP show the lowest values recorded and unprecedented negative trends in the late 1980s and 1990s. [...] The fraction of NSS and DWSP in different seasons (autumn, winter and spring) has changed only slightly over the ∼150 year record. Some decreases most likely attributable to temperature changes in the last 50 years are found for spring, especially for NSS at low stations. Both the NSS and DWSP snow indicators show a trend reversal in most recent years (since 2000), especially at low and medium altitudes. This is consistent with the recent ‘plateauing’ (i.e. slight relative decrease) of mean winter temperature in Switzerland and illustrates how important decadal variability is in understanding the trends in key snow indicators.”