Item: Analysis of Surface Hoar Growth Under Simulated Meteorological Conditions
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Title: Analysis of Surface Hoar Growth Under Simulated Meteorological Conditions
Proceedings: Proceedings, 2012 International Snow Science Workshop, Anchorage, Alaska
Authors:
- Brad Stanton [ Montana State University Bozeman, MT ]
- Daniel Miller [ Montana State University Bozeman, MT ]
- Edward Adams [ Montana State University Bozeman, MT ]
Date: 2012
Abstract: Surface hoar, essentially frozen dew, is known to form on cold, clear nights when radiant energy loss to the sky drives the surface temperature of the snow below the frost point temperature. As the surface temperature drops, the air above becomes supersaturated with respect to the snow causing the deposition of a faceted layer known as surface hoar. Few studies have attempted to grow surface hoar in a lab setting and none have replicated the radiant cooling process. In an environmental chamber at Montana State Universityʼs Subzero Science and Research Facility, surface hoar was grown using a cold ceiling to simulate long wave radiation loss to a clear sky. Air and snow temperature, wind speed, and supersaturation were carefully controlled in the lab. A time history of resulting laboratory crystal development was documented before, during, and after growth using both visible photography and 3D x-ray computed tomography (CT). Consistent with atmospheric crystal growth, results show surface hoar crystal habit varies with temperature. At snow surface temperatures of approximately -5°C and -30°C, c-axis dominant growth occurred, while at snow surface temperatures of approximately -13°C, a-axis dominant growth occurred. Additionally, specific surface area from CT scans indicated larger values for plate growth than for needles.
Object ID: issw-2012-179-185.pdf
Language of Article: English
Presenter(s): unknown
Keywords: hoarfrost, snow surface temperature, surface hoar, crystal growth
Page Number(s): 179-185
Subjects: surface hoar growth computed tomography x-ray
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