期刊名称：Cuadernos de Investigación Geográfica = Geographical Research Letters
印刷版ISSN：0211-6820
电子版ISSN：1697-9540
出版年度：2010
卷号：36
期号：1
页码：43-57
DOI：10.18172/cig.1226
出版社：Universidad de La Rioja
摘要：Snowpack aerodynamic surface roughness length (zo) is a critical variable in estimating heat transfers to and from a snow surface and thus sublimation rates. This variable has been shown to be site specific. To illustrate a temporal variation in zo, laboratory experiments were performed using a small evaporation pan sitting on a load cell with a constant wind flow over the snow surface. Comparing multi-layer meteorological data above the pan to sublimation measured from mass change showed a decrease in the snowpack surface roughness length as the snow metamorphosed. The sensitivity of snowpack zo changes over time in modeling of sublimation was examined using hourly meteorological data for the winter of 2000-2001 at Syracuse, New York and Leadville Colorado for several scenarios, including increasing or decreasing zo after a snowfall event, considering directionality of zo as a function of the wind direction, and a ratio of latent heat to momentum roughness lengths. The base case used a constant zo of 0.01 metres. The modeled differences were a function of the values of zo, which varied with the frequency of occurrence of fresh snow and the distribution of wind from various directions. The temporal and spatial variability in surface roughness is crucial in computing the energy and mass balance of a snowpack.
