書誌事項
- 公開日
- 2006
- 権利情報
-
- https://www.cambridge.org/core/terms
- DOI
-
- 10.3189/172756506781828430
- 公開者
- International Glaciological Society
この論文をさがす
説明
<jats:title>Abstract</jats:title><jats:p>Wind tunnel measurements of snowdrift in a turbulent, logarithmic velocity boundary layer have been made in Davos, Switzerland, using natural snow. Regression analysis gives the drift threshold friction velocity (u<jats:sub>*t</jats:sub>), assuming an exponential drift profile and a simple drift to friction velocity relationship. Measurements over 15 snow covers show that u<jats:sub>*t</jats:sub> is influenced more by snow density and particle size than by ambient temperature and humidity, and varies from 0.27 to 0.69 ms<jats:sup>–1</jats:sup>. Schmidt’s threshold algorithm and a modified version used in SNOWPACK (a snow-cover model) agree well with observations if small bond sizes are assumed. Using particle hydraulic diameters, obtained from image processing, Bagnold’s threshold parameter is 0.18. Roughness lengths (z<jats:sub>0</jats:sub>) vary between snow covers but are constant until the start of drift. Threshold roughness lengths are proportional to <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="gif" xlink:type="simple" xlink:href="S0022143000209337_inline23"/>. The influence of macroscopic objects on the roughness length is shown by the lower values measured over the smooth and flat snow surface of the wind tunnel (0.04 ≤ z<jats:sub>0</jats:sub> ≤ 0.13 mm), compared to field measurements. Mean drifting-snow grain sizes for mainly new and partly decomposed snow are 100–175 μm, and independent of surface particle size.</jats:p>
収録刊行物
-
- Journal of Glaciology
-
Journal of Glaciology 52 (179), 585-596, 2006
International Glaciological Society
