Monday, September 28, 2020
Neige Calonne, Météo-France/CNRS
Benjamin Reuter, Météo-France/CNRS
Carlo Carmagnola, Météo-France/CNRS
Sponsored by GRSS
GRSS Webinar: Essential Snow Measurement Techniques
This webinar demonstrates and discusses snow measurement instruments and techniques. Properties measured include density, specific surface area, hardness, and grain size. The ramsonde is an instrument used for snow layer identification. A thermometer is used for measuring snow temperature on the surface and at depth. Another instrument is a crystal screen for identifying grain sizes and roughness of different snow layers. Hardness is estimated by progressively using a finger, a pencil, and knife for each layer. One can also collect a certain volume, using a cylindrical or rectangular holder, and then weigh it to get density, for each layer. Specific surface area is measured using something called DUFISSS, or dual-frequency integrating sphere for snow specific area measurements, which uses infrared reflection from snow. The Snow Micro Penetrometer, or SnowPen, measures the penetration resistance to a pointed rod driven through the snow. From this measured force one can infer three parameters: rupture force, deflection at rupture, and the structural element length. Once can then infer the elastic modulus as well. This is done as a function of depth.
Liquid water content is measured using an instrument called WISE, which measures the permittivity of a snow volume. Given a measurement of density one can then calculate the liquid water content.
Neige Calonne is a researcher at METEO FRANCE. She received her PhD at the Université de Grenoble in 2014. Her research work aims to study and characterize the physical processes and microstructure of snow from the scale of ice grains to that of snow layers. By relying in particular on experimental tools, field measurements, and homogenization approaches, the aim is to improve the description of physical processes in snowpack models.
Benjamin Reuter is a Postdoctoral Researcher at METEO FRANCE. He received his PhD in Atmospheric Sciences and Meteorology at ETH Zürich in 2015.
Carlo Carmagnola is a Post-doc scientist at Météo-France. He received his PhD at Météo France – CNRS, CNRM – GAME, Centre d’Études de la Neige, Grenoble, France in 2013.