European In-Situ Snow Measurements: Practices and Purposes

TLDR

European institutions conduct in‑situ snow measurements across diverse environments—from mountains to urban areas—to monitor bulk snow properties essential for hydrology, avalanche forecasting, and weather prediction, as surveyed under COST Action ES1404. The survey aims to improve the efficiency and coverage of the in‑situ snow observation network by recommending automated, low‑cost measurement methods and harmonized practices. Most measurements are performed manually, with some respondents using automated techniques for snow presence, depth, and water equivalent. The survey, answered by 125 participants from 99 institutions across 38 countries, found that 93 % measure macrophysical snow properties, 74 % record precipitating and suspended snow parameters, while 41 %, 26 %, and 13 % assess microstructural, electromagnetic, and compositional characteristics, respectively.

Abstract

In-situ snow measurements conducted by European institutions for operational, research, and energy business applications were surveyed in the framework of the European Cooperation in Science and Technology (COST) Action ES1404, called “A European network for a harmonised monitoring of snow for the benefit of climate change scenarios, hydrology, and numerical weather prediction”. Here we present the results of this survey, which was answered by 125 participants from 99 operational and research institutions, belonging to 38 European countries. The typologies of environments where the snow measurements are performed range from mountain to low elevated plains, including forests, bogs, tundra, urban areas, glaciers, lake ice, and sea ice. Of the respondents, 93% measure snow macrophysical parameters, such as snow presence, snow depth (HS), snow water equivalent (SWE), and snow density. These describe the bulk characteristics of the whole snowpack or of a snow layer, and they are the primary snow properties that are needed for most operational applications (such as hydrological monitoring, avalanche forecast, and weather forecast). In most cases, these measurements are done with manual methods, although for snow presence, HS, and SWE, automatized methods are also applied by some respondents. Parameters characterizing precipitating and suspended snow (such as the height of new snow, precipitation intensity, flux of drifting/blowing snow, and particle size distribution), some of which are crucial for the operational services, are measured by 74% of the respondents. Parameters characterizing the snow microstructural properties (such as the snow grain size and shape, and specific surface area), the snow electromagnetic properties (such as albedo, brightness temperature, and backscatter), and the snow composition (such as impurities and isotopes) are measured by 41%, 26%, and 13% of the respondents, respectively, mostly for research applications. The results of this survey are discussed from the perspective of the need of enhancing the efficiency and coverage of the in-situ observational network applying automatic and cheap measurement methods. Moreover, recommendations for the enhancement and harmonization of the observational network and measurement practices are provided.