The Seasonal Snow Cover Dynamics: Review on Wind-Driven Coupling Processes

Abstract

The temporal evolution of seasonal snow cover and its spatial variability in environments such as mountains, prairies or polar regions is strongly influenced by the interactions between the atmospheric boundary layer and the snow cover. Wind-driven coupling processes affect both mass and energy fluxes at the snow surface with consequences on snow hydrology, avalanche hazard, and ecosystem development. This paper proposes a review on these processes and combines the more recent findings obtained from observations and modeling. The spatial variability of snow accumulation across multiple scales can be associated to wind-driven processes ranging from orographic precipitation at large scale to preferential-deposition of snowfall and wind-induced transport of snow on the ground at smaller scales. An overview of models of varying complexity developed to simulate these processes is proposed in this paper. Snow ablation is also affected by wind-driven processes. Over continuous snow covers, turbulent fluxes of latent and sensible heat, as well as blowing snow sublimation, modify the mass, and energy balance of the snowpack and their representation in numerical models is associated with many uncertainties. As soon as the snow cover becomes patchy in spring local heat advection induces the development of stable internal boundary layers changing heat exchange toward the snow. Overall, wind-driven processes play a key role in all the different stages of the evolution of seasonal snow. Improvements in process understanding particularly at the mountain-ridge and the slope scale, and processes representations in models at scales up to the mountain range scale, will be the basis for improved short-term forecast and climate projections in snow-covered regions.

Water Losses During Technical Snow Production: Results From Field Experiments

“…From our measurements, we cannot directly quantify losses attributed to wind drift. Physically based models (see e.g., Mott et al, 2018) could possibly be applied to simulate deposition of snow during snow-making. Results could help to evaluate how much snow might be accumulated outside the measured area.…”

Comments and suggestions

“…Printer-friendly version Discussion paper Mott et al 2018; these references and possible also other earlier work should be cited in context of the discussion; L11 what is the "R-value"? Section 7: Conclusions should be prolonged; Here all three research questions form the introduction should be shortly answered; an outlook on future research that might be useful to enhance our understanding on snow storage might also be added; Figure 7: Why is the increase in volume from April 1 to May 1 for site 2 so much larger than for site 1?…”

Synoptic and meteorological conditions during extreme snow cover ablation events in the Great Lakes Basin

“…The magnitude of individual turbulent and radiative fluxes can vary considerably intra‐annually and, when positive (into the snowpack), work to ablate snow. Net radiation is often noted as the primary driver for ablation across the course of the winter season (Cullen & Conway, ; Mott, Vionnet, & Grunewald, ); however, individual meteorological events leading to increased wind speeds, warm and moist air advection, and/or liquid precipitation can generate relatively large turbulent energy fluxes, which can dominate the snowmelt energy signal (Dadic et al, ; Gillet & Cullen, ; Mott et al, ).…”