No abstract

A simple model is proposed for the solar albedo of natural snow cover, based on an approximation to the specific surface by a function of grain size and density derived from air permeability measurements. Agreement with limited observational material is good. The model suggests that for grain sizes greater than 1.5 mm, density is the primary factor governing albedo.

No abstract

Illumination at various levels in an undisturbed snow cover was measured with CdS cells at intervals during the winter, along with air permeability and density. Extinction coefficients for particular layers increased with time. Measured values in the snow layer near the soil ranged from 0.072 cm−1 to 0.313 cm−1, computed as an average for light in the 0.5 to 0.7‐μ region. Coefficients for higher levels varied from 0.059 cm−1 to 0.148 cm−1. A relation between the extinction coefficient, air permeability, and density based on the Carmen‐Kozney assumption predicts the observed values with fair accuracy.

ABSTRACT. Snow-cover settlement was measured in a dry, annual sub-alpine snow cover in the Colorado Rockies with settlement gages. Settlement viscosities were calculated from the change in gage heights over various periods during the winter and early spring, and the associated overburden over the gages as estimated from density measurements and precipitation records. When adjustments are made for local snow temperature, viscosities are in fair agreement with values found in the literature from similar snow covers, although considerable scatter for a given snow density is found in all sets compared. The viscosity for a given density does not appear to vary systematically with grain size. RESUME. Quelques mesures de tassement dans le manteau neigeux des Rocky Mountains. On a mesure le tassement de la neige dans le manteau annuel de neige seche en zone subalpine dans les Rocheuses du Colorado avec des jauges de tassement. Les viscosites de tassement ont 6t6 calcul^es a partir des changements constates dans la hauteur de neige pendant des periodes variees au cours de l'hiver et du debut du printemps, et les surcharges qui leur sont associees sur les jauges estimees a partir de mesures de densite et d'enregistrement des precipitations. Lorsqu'on fait les corrections pour la temperature locale de la neige, les viscosites sont en bon accord avec les valeurs pour des manteaux neigeux comparables reperes dans la litterature, bien qu'il y ait une dispersion considerable pour une densite donnee entre les differents echantillons compares. La viscosite pour une densite donnee ne semble pas varier systematiquement avec la grosseur des grains. ZUSAMMENFASSUNG. Einige Messungen der Setzung einer Schneedecke in den Rocky