Determining the drivers for snow gliding

Abstract

Abstract. Snow gliding is a key factor for snow-glide avalanche formation and soil erosion. This study considers atmospheric and snow variables, vegetation characteristics, and soil properties and determines their relevance for snow gliding at a test site (Wildkogel, Upper Pinzgau, Austria) during winter 2014/2015. The time-dependent data were collected at a high temporal resolution. In addition to conventional sensors, a “snow melt analyzer” was used. The analysis shows that the soil temperature 10 cm below the surface, the phytomass of mosses, the liquid water content in the snowpack, and the static friction coefficient of the glide shoes had significant influence on snow gliding during the whole winter. In the first period (October to January) the soil moisture at the surface and 1.5 cm below the surface and the length of the slope uphill of the glide shoes affected the snow gliding, too. In the second period (February to May) the soil temperature at the surface, the soil moisture 10 cm below the surface, and the slope angle had additional influence on snow gliding. The role of the vegetation in the snow-glide process is determined by the influence on the static friction coefficient caused by its composition and characteristics and by moss-rich and short-stemmed canopies being seemingly more interconnected with the snowpack. In addition to the soil and snow properties, the topography and the vegetation characteristics, further investigations may be focused on the freezing and melting processes in the uppermost soil layers and at the soil surface.

Snow gliding and glide-snow avalanches: recent outcomes from two experimental test sites in Aosta Valley (northwestern Italian Alps)

“…For example, in Pista Nera the VLWC in the snow was significantly higher for gliding than for non-gliding periods when considering the whole dataset or cold periods. This was also found by Fromm et al (2018) and Ceaglio et al (2017). Instead, in Sant'Anna there was no difference in the VLWC of snow during cold periods; a little significant difference was found in warm periods, but the VLWC of snow was higher in non-gliding than in gliding periods, revealing how other predisposing factors could contribute to the snow gliding process.…”

“…As WCR probes were mainly designed to measure volumetric liquid water content in soils, we were able to transform the values recorded by the instrument place in the basal snowpack layer following the corrections found by Godio et al (2018) during an experimental campaign carried out at the vicinity of the manual measuring site of Sant'Anna.…”

“…The most recent studies by Ceaglio et al (2017) and Fromm et al (2018) underline the importance of soil moisture as a driving factor for snow gliding. In particular, Ceaglio et al (2017) found a strong relation between glidesnow rate and moisture at the snow-soil interface for cold temperature events, also with a possible contribution of soil liquefaction, while Fromm et al (2018) found that soil moisture and temperature had a significant influence on snow gliding in both warm and cold periods.…”

“…As in Ceaglio et al (2017) and Fromm et al (2018), this work, using an experimental approach, starts from data gathered at two test sites and aims at giving a contribution to the ongoing scientific discussion on the most important driving factors for snow gliding and glide-snow avalanches. Our goal is to quantify the linkages between soil water content and snow gliding processes and to assess the factors predisposing the glide avalanche release, under different meteorological and snowpack conditions (warm vs. cold events).…”

Snow gliding and glide snow avalanches: recent outcomes from two experimental test sites in Aosta Valley (NW Italian Alps)

“…The most recent studies by Ceaglio et al (2017) and Fromm et al (2018) underline the importance of soil moisture as a driving factor for snow gliding. In particular, Ceaglio et al (2017) found a strong relation between glide snow rate and moisture at the snow-soil interface for cold temperature events, with a possible contribution also of soil liquefaction, while Fromm et al (2018) found that soil moisture and temperature had a significant 15 influence on snow gliding in both warm and cold periods.…”