WG 2: Instrument and Method Evaluation

Task 2.1: A review of existing space-borne and ground-based sensors/instrumentation applied for measurement of different snow characteristic, estimation of their uncertainties.

Task 2.2: Guidelines for in-situ snow observations and related training: Accuracy of various methods and instruments; Error sources for different variables under various weather and snow conditions; Representativeness of point measurements of the different variables; Need for measurement lines with recommended length and sampling resolution.

Task 2.3: Spectroradiometry for snow studies: How to make consistent field spectrometer measurements of snow pack (environmental parameters including viewing and illumination geometry, snow cover characterization including grain size characteristics of the top-snow-layer). How to process the data in a harmonized way (e.g. spectral sampling, geo-rectification in case of airborne measurements, filtering techniques for continuous spectra).

Task 2.4: Methods to measure snow grain size: The methods for snow grain size detection are under development worldwide, and currently the definition of grain size varies greatly depending on the method used. The increasing number of grain size measurement techniques has reached a stage where their thorough assessment and inter comparison is mandatory.

Task 2.5: Methods to measure mechanical properties of snow: Mechanical properties are of relevance to snow stability, and consequently to snow avalanche formation. Field tests of snow stability should be harmonized within the European avalanche services, as well as the testing of snow properties using modern snow penetrometry (SnowMicroPen).

WG2 is connected to WG1 with regards to the definition of the measured snow variables and toWG3 in terms of observation uncertainties.