Air temperature control on snow erosion at a high-elevation site in the Eastern European Alps

Snow accumulation on glaciers typically exhibits high spatial and temporal variability, especially on high-elevation and exposed areas, where wind action (e.g., preferential deposition, redistribution, erosion) can deeply modify snow accumulation patterns. Yet, wind action remains one of the most challenging processes to account for in glacier mass-balance models. In fact, the latter often treat snow accumulation by assuming a simple proportionality with precipitation, overlooking the influence of wind and its variability in space and time.

A critical issue, among others, regards the susceptibility of the snowpack to wind erosion. This susceptibility is controlled by the metamorphism of snow, which depends on the surface energy balance and time. In this study, we investigate how the susceptibility to erosion at the Alto dell’Ortles glacier (3905 m a.s.l., Eastern Alps, Italy) responds to high-elevation meteorological conditions. More in detail, on Mt. Ortles we focus on the influence of air temperature as it might lead to important feedbacks regulating snow accumulation and its seasonality in the context of climate change.

Few works exist in the scientific literature addressing the relationship between snow susceptibility to erosion and air temperature. We address this knowledge gap by calculating the energy and mass balance at a site close to the summit of Mt. Ortles, using the physically based process-oriented SNOWPACK model, which explicitly accounts for snow erosion by wind. The model is driven by meteorological data from an automatic weather station (AWS) located on the glacier’s upper accumulation zone (3830 m a.s.l.) and precipitation data recorded at the nearby Solda AWS (1907 m a.s.l.). The model is evaluated against automatic snow depth measurement series and periodic mass balance observations spanning 2011–2015.

This approach enables the systematic assessment of snowpack susceptibility to wind erosion under varying air temperature, considering its effects during the formation of snow layers and during their permanence at the glacier surface. In particular, we observe increasing resistance to wind erosion for increasing mean temperature during the permanence of a layer at the surface. The results enable to shed light on the long-term behaviour of this high-elevation glacial site, which shows persistent net snow accumulation despite ongoing atmospheric warming. 

This study was carried out within the RETURN Extended Partnership and received funding from the European Union Next-Generation National Recovery and Resilience Plan (NRRP, Mission 4, Component 2, Investment 1.3 – D.D. 1243 2/8/2022, PE0000005).