Swiss Federal Institute for Forest, Snow and Landscape Research

About: Swiss Federal Institute for Forest, Snow and Landscape Research is a facility organization based out in Birmensdorf, Switzerland. It is known for research contribution in the topics: Climate change & Soil water. The organization has 1256 authors who have published 3222 publications receiving 161639 citations. The organization is also known as: WSL.

Shorter snow cover duration since 1970 in the Swiss Alps due to earlier snowmelt more than to later snow onset

Abstract: Global warming has strong impacts on snow cover, which in turn affects ecosystems, hydrological regimes and winter tourism. Only a few long-term snow series are available worldwide, especially at high elevation. Here, we analyzed several snowpack characteristics over the period 1970–2015 at eleven meteorological stations, spanning elevations from 1139 to 2540 m asl in the Swiss Alps. Snow cover duration has significantly shortened at all sites, on average by 8.9 days decade−1. This shortening was largely driven by earlier snowmelt (on average 5.8 days decade−1) and partly by later snow onset but the latter was significant in only ~30 % of the stations. On average, the snow season now starts 12 days later and ends 26 days earlier than in 1970. Overall, the annual maximum snow depth has declined from 3.9 to 10.6 % decade−1 and was reached 7.8 ± 0.4 to 12.0 ± 0.4 days decade−1 earlier, though these trends hide a high inter-annual and decadal variability. The number of days with snow on the ground has also significantly decreased at all elevations, in all regions and for all thresholds from 1 to 100 cm. Overall, our results demonstrate a marked decline in all snowpack parameters, irrespective of elevation and region, and whether for drier or wetter locations, with a pronounced shift of the snowmelt in spring, in connection with reinforced warming during this season.

Tree-ring width and density data around the Northern Hemisphere: Part 2, spatio-temporal variability and associated climate patterns

Abstract: Patterns of summer temperature over the Northern Hemisphere, obtained from a calibration of a treering network, are presented for every year from 1600 to 1877 The network of tree-ring density chronologies is shown to exhibit spatially coherent modes of variability These modes closely match summer half-year tempera ture variations, in terms of similar spatial patterns and similar temporal evolution during the instrumental period They can, therefore, be considered to be proxies for the temperature patterns, and time series for the eight most dominant patterns are presented back to the late seventeenth century The first pattern represents spatially coherent warming or cooling and it appears to respond to climate forcings, especially volcanic erup tions Most other patterns appear to be related to atmospheric pressure anomalies and they can be partially explained by heat advection associated with anomalous atmospheric circulation This provides the potential for reconstructing past variations in atmospher