Dust on Snow, Ice Column Formation, and Meltwater Flow Paths at Niwot Ridge

TitleDust on Snow, Ice Column Formation, and Meltwater Flow Paths at Niwot Ridge
Publication TypeConference Proceedings
Year of Conference2010
AuthorsPetrzelka, J., Williams M., and Zukiewicz L.
Conference Name78th Annual Western Snow Conference
Series TitleProceedings of the 78th Annual Western Snow Conference
Date PublishedApril 2010
PublisherWestern Snow Conference
Conference LocationLogan, UT
KeywordsNiwot Ridge, meltwater, ice columns, dust on snow, flowpaths, surface roughness, albedo

The presence of dust on the snow's surface has been shown to decrease albedo by as much as 40% compared to a clean snow cover. Thus dust on snow affects snow surface radiative fluxes, generally resulting in earlier snowmelt compared to clean snowpacks. Less understood is how dust on snow events may affect infiltrating meltwater movement in the snowpack. An aeolian dust event with a distinctive red color that was deposited in February of 2006 at Niwot Ridge in the Colorado Front Range provides opportunity to investigate how dust on snow may change the surface characteristics of snow and meltwater movement through the snowpack. Ice columns found in clean snow had a mean depth of 60 cm, which was significantly longer (p=0.0001) compared to the mean depth of 16.7 cm in red snow. The shape also varied, with ice columns in clean snow having a uniform width along the entire length, whereas those found in red snow were widest at the snow surface and decreased in width with depth. The movement of liquid water through the snowpack in red snow appears to be more uniform, decreasing the size of preferential flowpaths that give rise to ice columns when compared to clean snow. Thus the variation in ice column morphology between red and clean snow gives insight into how dust deposition events may affect the energy balance, subsequent melt, and meltwater flowpaths in snow covered areas