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How efficient is snowmaking?

04/10/2017

The use of machine-made snow is increasing in most French ski resorts. However, this method of preparing the slopes can be controversial, and the range of issues associated with the practice has led to research. A new study led by the French Center for Studies of Snow (CEN 1, Météo-France/CNRS) and Irstea Grenoble 2 has focused on precisely quantifying the efficiency of current snowmaking processes. Although they do not address the issue of using machine-made snow to maintain skiable areas during variable weather conditions, the results are likely to lead to improved technical recommendations for the acquisition and use of snowmaking machines. The results have been published in the journal The Cryosphere3 of April 7, 2017.

Machine-made snow is made by freezing microdroplets of water and spraying them through a device known as a snow gun. According to snow gun manufacturers and the first scientific studies into the subject, the process is characterized by a 10% loss of water. However, observations made by CEN and IRSTEA in Alpine ski resorts during the 2014-2015 season demonstrated 4 that the amount of machine-made snow found on ski slopes equipped with snow guns was in reality much smaller than that expected in theory. In order to verify and confirm these observations, a series of specific measurements were taken during the 2015-2016 season in the Deux Alpes resort (Isère) using a novel application of glaciological measuring tools 5 and a laser scanner.

 The results, published on April 7, 2017 in The Cryosphere, confirm that a significant amount of the water used in producing the snow is not recovered as snow on the slopes, with this amount being proportionally dependent on production conditions: topography of the area (gradient of ski slope borders, plant cover), location of snow guns and meteorological conditions (temperature and wind).

 The amount of water missing from the slope, excluding the unchangeable fraction of around 10% linked to the manufacturing process, is usually deposited beyond the limits of the slopes, either due to the strength of the jet or to wind and local topography. This proportion can vary from one production session to another depending on meteorological conditions and is particularly likely to be affected by local characteristics.

 This type of study is particularly relevant for socioeconomic stakeholders (resort managers and equipment manufacturers) as the energy and environmental costs of snowmaking mean that losses need to be minimal. It is also essential in the quantitative analysis of water and energy required to produce the amounts of snow needed to meet strategic operational requirements.

CEN, IGE and the Irstea teams involved are laboratories and teams linked to the Grenoble Observatory of Earth Sciences, Astronomy and Astrophysics (OSUG).

For further information: 

 

1 Team based in Grenoble at the National Center for Meteorological Research (CNRM, Météo-France/CNRS)
Via its Development of Mountainous Regions and Stream Erosion, Snow and Avalanches research units.
Spandre, P., H. François, E. Thibert, S. Morin, and E. George-Marcelpoil, Determination of snowmaking efficiency on a ski slope from observations and modelling of snowmaking events and seasonal snow accumulation, The Cryosphere, 11, 891-909, doi:10.5194/tc-11-891-2017, 2017.
Spandre, P., S. Morin, M. Lafaysse, Y. Lejeune, H. François and E. George-Marcelpoil, Integration of snow management processes into a detailed snowpack model, Cold Reg. Sci. Technol., 125, 48-64,doi :10.1016/j.coldregions.2016.01.002, 2016
Made available by the Institute for Geosciences and Environmental research (IGE)