Glacier monitoring in Switzerland: Challenges and opportunities
by Dr. Matthias Huss, Dr. Andreas Bauder, Dr. Andreas Linsbauer

Abstract

Glaciers are a headline indicator for global climate monitoring. Changes in mass and extent of mountain glaciers and ice caps worldwide are closely related to long-term shifts in temperature, precipitation and radiation forcing. Glaciers therefore integrate various aspects of the meteorology and express climate change in an impressive, visual fashion that is highly important for communicating the climate crisis to a broader public. Standardized long-term observations of glacier changes are crucial for enhancing process understanding, or for calibrating and validating numerical models that can be used to reconstruct past glacier fluctuations, or to project future glacier retreat. In Switzerland, some of the longest and most continuous observational series on glacier changes are available. The measurements partly span more than a century and are well documented. The national programme Glacier Monitoring Switzerland (GLAMOS) is responsible for maintaining, evaluating and disseminating these series. Here, challenges and opportunities in current long-term glacier monitoring are discussed, including possible ways forward. Climate change itself poses a major threat to the continuity of the glaciological measurements. Several glaciers with long-term monitoring series are on the verge of melting completely, or have already been lost. Early recognition of such cases and the selection of more resilient sites, with an appropriate temporal overlap with the series to be abandoned, is vital for ensuring the continuity of the monitoring. Emerging new measurement techniques, for example based on remote sensing or automated monitoring stations deployed on glaciers, represent a major opportunity to evolve the network. Nevertheless, a careful analysis of the accuracy and a potential bias with more traditional methods is needed before such new technologies can be used for a reliable continuation of multi-decadal measurements. Modelling is an indispensable tool to interpret and extrapolate local measurements, or to transform them into a useful, comparable quantity. However, a comprehensive estimate of the uncertainties related to such approaches is instrumental for further using the data products. Using various examples, the challenges and opportunities outlined above will be explored from the point of view of Swiss glacier monitoring.