Evaluating ablation and environmental impact of giant anthropogenic snow patches (Yuzhno-Sakhalinsk, Russia)

Abstract

Systematic snow disposal from street cleaning operations may create large anthropogenic snow/ice bodies. Such man-made cryospheric objects may be considered as complex geophysical interfaces between the atmosphere, landscape, soils and hydrosphere. Urban snow patches not only produce large amounts of meltwater (and therefore a risk of flooding), but also serve as multiphase chemical reactors due to highly polluted mixture of snow/ice with various materials and water inclusions. However, the exact roles of snow patches in the environment and the factors driving their temporal evolution remain unclear. They are nevertheless of major importance for informed decision making and sustainable disposal operations. Here we present the results of a 4-year monitoring program concerning two artificial snow patches near the town of Yuzhno-Sakhalinsk (Russia) and the results of numerical modeling inferring the main corresponding processes, i.e. melting and water discharges. The temperature-based index method proved adequate to assess the evolution of the two snow patches. Constant ablation factors of about 0.45-0.58 and 0.27-0.31 cm w.e. d −1°C−1 , respectively, were found to be appropriate for a first order approximation of snow patch melt dynamics. However, twice lower melt rates were found for one of the two closely located snow patches. This suggests that other factors, such as debris content, likely play a role. This difference in melting can be accounted for by modulating the ablation factor according to debris properties. In terms of peak daily water discharge, snow patch melting produces about 5-15 cm w.e. per day, comparable to rain rates during regional typhoons. This study represents a starting point that should be followed by a more detailed monitoring program and the application of a more complex numerical model of snow disposal sites, to allow optimization of their maintenance. For example, marginal melting or the combined influence of debris and soils on surface runoff should be further investigated. Moreover, better constrained and formulated chemical processes will allow a more reliable estimate of the local environmental impact of regular snow disposal.

Snow storage – Modelling, theory and some new research

“…However, mineral wool and other materials without capillary water transport will benefit from lower thermal conductivity but suffer from omitted evaporative cooling. The results of debris or mineral particles as a thermal insulation on snow have been observed on glaciers and anthropogenic snow patches, where the melt rate decreases with thickness of the debris layer (Pelto, 2000;Kayastha et al, 2000;Takeuchi et al, 2000;Podolskiy et al, 2015). In contrast to wood chips, there is no decay of debris and thus a one-time cost, if chosen as thermal insulation on a snow depot (Skogsberg, 2005).…”

Viscoelastic Modeling of Nocturnal Thermal Fracturing in a Himalayan Debris‐Covered Glacier

“…This is particularly important because it may correspond to a strong and largely overlooked weathering agent of glacier ice. No focused analysis of the relationship between thermal stress and ice fracturing has been made on debris‐covered glaciers to date, despite recent interest in the role of debris on the mass balance of glaciers and snow patches (e.g., Fujita & Sakai, ; Podolskiy et al, ). The main possible factors that lead to the processes observed by Podolskiy et al () are (1) the elastic response of the ice, (2) high diurnal temperature fluctuations, and (3) weak ice with high stress at heterogeneities.…”