The effect of aeolian deposition on the surface roughness of melting snow, Byers Peninsula, Antarctica

Abstract

Abstract:The surface of the snowpack is the bottom boundary layer for air movement, and its roughness influences aerodynamics. The presence of aeolian deposits on a snowpack decreases its albedo and is shown to decrease the roughness of the surface. During snowmelt in the Lake Limnopolar basin on Byers Peninsula of Livingston Island of the South Shetland Islands, Antarctica, wind moved coarse soil grains (1-4 mm particles) from a bare, dry and snow-free area to an adjacent snowpack. This addition of large soil particles rapidly changed the snowpack surface characteristics. Within several days, the sun-cups, initially present on the melting snow surface, had been smoothed out in areas where soil was deposited on the snow surface. The differences in the snowpack surface were assessed using digital imagery of a roughness board inserted into the snow, both parallel and perpendicular to the dominant wind direction. The random roughness was twice as variable for the clean snow compared to the snow with soil; it was 27% more and 26% less perpendicular versus parallel to the wind for the clean snow and snow with soil, respectively. Variogram analysis showed that the clean snow had up to four different scales of roughness over the 55 ð 55 cm area of analysis, with fractal dimensions varying from 1Ð33 to 1Ð83. The snow with soil did not vary substantially from 0Ð1 to 55 cm with fractal dimensions of 1Ð65 in parallel and perpendicular to the wind.

Mapping snow cover and snow depth across the Lake Limnopolar watershed on Byers Peninsula, Livingston Island, Maritime Antarctica

“…Winds blow mostly from the west with average speeds from 5–15 m s -1 during peak accumulation (Fassnacht et al . 2010).…”

A review of scientific research trends within ASPA No. 126 Byers Peninsula, South Shetland Islands, Antarctica

“…(2004) described the physicochemical properties of various waters in a permafrost area of Byers Peninsula, and Fassnacht et al . (2010) studied the effect of aeolian deposition on the surface roughness of melting snow. Byers Peninsula was recently included in the CALM (Circumpolar Active Layer Monitoring) programme, locating a new CALM-S site near the south-west shore of the Limnopolar Lake (De Pablo et al .…”

Measuring glacier surface roughness using plot-scale, close-range digital photogrammetry

“…Mineral dust content and associated biological consortia can significantly increase the shortwave incident radiation contributing to melt on snow (Warren, 1984; Kohshima and others, 1994; Thomas and Duval, 1995; Conway and others, 1996; Painter and others, 2007) and glacier ice (Kohshima and others, 1993; Adhikary and others, 2000; Takeuchi, 2002) where water content is similarly influential (Cutler and Munro, 1996). Consequently, topography can become exaggerated or inverted as the relative proportions of radiative and turbulent energies vary, particularly at synoptic timescales (Müller and Keeler, 1969; McIntyre, 1984; Rhodes and others, 1987; Fassnacht and others, 2010). Such dynamics of snow/ice surface roughness modulates the response of remote satellite-mounted sensors, particularly those utilizing microwave wavelengths whose data products relate to signal backscatter and surface dielectric properties (Jin and Simpson, 1999; König and others, 2001; Nolin and others, 2002).…”