Short-Term Snow Melt and Ablation Derived from Heat- and Mass-Balance Measurements

Abstract

The daily snow melt calculated from meteorological observations is compared with detailed mass-balance measurements taking into account internal changes in density and free water content in the surface layers of a glacier snow-pack. The energy balance is calculated from measurements obtained by a meteorological station at the experimental site. In addition to the standard ablation measurements the run-off from the melting snow-pack was obtained for a few days. The snow-density profiles were measured with a portable gamma-transmission probe and the liquid-water content of snow was determined by a calorimetric method.Agreement between the melt calculated by the heat-balance method and the mass changes observed in the mass-balance measurements is fair for daily periods. It appears that about 20% of the daily snow melt takes place internally as a result of penetration of solar radiation.

Glacier contribution to the North and South Saskatchewan Rivers

“…The hydrological balance for each basin was calculated with the glacier runoff as the residual, glacier runoff was defined as total runoff from the glacierised area of each basin, therefore including snowmelt from the accumulation area and any precipitation (snow and/or rain) that fell on the glacier surface during this time period. Glacier cover and measurements of snow accumulation for the non-glacier portions of the basin were taken from air photographs, evaporation and condensation were assumed to be zero (based on Fohn's (1973) finding that these two components are approximately equal over snow, and net evaporation over the non-glacierised area is small), change in storage was assumed zero, and precipitation was measured at climate stations. For non-gauged glaciers in the Mistaya basin, glacier runoff was estimated by extrapolating Peyto summer mass balance data collected in three time periods from 5 th May to 15 th September.…”

A Recording Snow Lysimeter

“…Recent mass and energy balance studies of glaciers and snow fields of large area have revealed a need for basic investigations into the ablation mechanisms relating to ice and snow (Fohn, 1973;Wendler and Ishikawa, 1973;Ambach, 1976). A study into the development of temperate winter snow covers has been carried out by the Institut fur Geographie der Universitat Munchen since 1971; this research is part of a long-term hydrological research programme (Herrmann and others, 1973).…”

Evaposublimation from the snow in the Mediterranean mountains of Sierra Nevada (Spain)

“…This method, also known as gravimetric, involves measuring the changes in mass of a finite volume of snow. Snow evaporation pans have been used for over forty years by, for example, Doty and Johnston (1969), Föhn (1973), Lemmelä and Kuusisto (1974), and Bengtsson (1980). It must be noted that, under precipitation or windy conditions which can blow the snow into or out of the pan, there may be a variation in the mass measured in the control volume that will not be directly distinguishable from evaposublimation unless it is measured separately.…”

“…A final approach is based on the evaporation pan method (Doty and Johnston, 1969;Föhn, 1973;Lemmelä and Kuusisto, 1974;Avery et al, 1992;Radionov et al, 1997;Hachikubo, 2001). This traditional technology is a simple, inexpensive, and portable means of measurement based on the monitoring of a sample of snow collected in situ into a container that does not appreciably alter the natural snow conditions.…”