CGRG Bibliography of Canadian Geomorphology
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Author : Cutler, P.M; and Munro, D S.
Date : 1996
Title : Visible and near-infrared reflectivity during the ablation period on Peyto Glacier, Alberta, Canada
Publication : Journal of Glaciology
Issue : 42(141):
Page(s) : 333-340
Abstract
Models for calculating glacier mass balance are sensitive to surface reflectivity variation. Fieldwork carried out on Peyto Glacier, Alberta, Canada, contributes to the data set available for ice-reflectivity parameterization in such models. Hemispherical reflectivity in the visible and near-infrared parts of the solar spectrum was obtained for rock, snow and three contrasting glacier surfaces to examine temporal and spatial variations. Glacier-ice near-infrared reflectivity displays only minor spatial variation (0.12-0.17) in comparison with the visible range (0.23-0.40), the latter being influenced primarily by surface impurity content. Surface roughness is of minor importance compared with impurities. Temporal variation of reflectivity was weak at all glacier-ice and rock locations; slight variations observed were due to changes in either solar zenith angle or cloud amount. Snow reflectivity displayed pronounced diurnal asymmetry and a larger response to cloud cover. The minimal temporal variation in glacier-ice reflectivity simplifies its parameterization. This behaviour is additionally useful for satellite-based measurements of tile reflectivity field on larger glaciers, as images obtained within a 6 h window centred on solar noon are likely to yield values which are within 2-3% of daily mean values.
Bibliography of Canadian Geomorphology