European In-Situ Snow Measurements: Practices and Purposes

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.

Impact of a Multi‐Layer Snow Scheme on Near‐Surface Weather Forecasts

“…Also the use of a prognostic snow grain size in regional climate models has been shown to improve the representation of snow albedo in high‐latitude regions compared to an empirical albedo parametrization (see Kuipers Munneke et al, ). The validation of such parametrizations in global NWP models requires more in situ observations of snow microphysical and radiative properties, in addition to standard snow depth and mass measurements (e.g., Pirazzini et al, ). Preliminary sensitivity experiments using a simple decomposition of snow albedo in the visible/near‐infrared bands showed improvements in the simulation of the 2‐m temperature over Antarctica and will be subject of future studies.…”

Retrieval of Snow Water Equivalent, Liquid Water Content, and Snow Height of Dry and Wet Snow by Combining GPS Signal Attenuation and Time Delay

“…The snow cover properties SWE, snow height (HS), and snow wetness, mainly expressed as snow liquid water content (LWC), can be measured at different scales. This includes on the one hand various in situ and point scale measurements (Kinar & Pomeroy, ; Lundberg et al, ; Pirazzini et al, ), which may provide continuous data but cannot capture spatial variations. On the other hand, optical and microwave remote sensing applications (Dietz et al, ; Hall, ; Nagler et al, ; Tedesco, ) can cover larger areas but might lack the desired temporal frequency or pixel resolution.…”

Multidisciplinarity in Research of Extreme Solar Energy Influences on Natural Disasters

“…Observation techniques of terrestrial parts that can be applied for natural disaster monitoring are numerous. They can be based on in situ measurements [32,33] or remote sensing from the ground or satellites [34,35].…”