CGRG Bibliography of Canadian Geomorphology
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Author : Cutler, P.M.
Date : 1991.
Title : Visible and near-infrared reflectivities in a mid-latitude glacier basin.
Publication : Unpublished MSc thesis. University of Toronto, Toronto.
Issue :
Page(s) :
Abstract
Five surfaces on Peyto Glacier, Alberta were examined, namely clean (and planar), dirty (planar) and hummocked glacier ice, metamorphosed snow and moraine. The ice sites were selected to represent extreme surface types (excluding crevasses). At ice and snow sites VISHR was always greater than the concurrent NIRHR reading, however over moraine the behaviour was reversed. NIRHR showed minimal spatial variation when compared with VISHR, the major control being impurity content. Introduction of surface roughness lowers afternoon values in both spectral regions. Temporal variation of hemispherical reflectivities was particularly weak at the ice and moraine sites. NIRHR demonstrated greater variation than VISHR, with dominant influences from solar zenith angle and cloud presence. Directional radiances for \Theta\sb{\rm r} = 85\sp\circ illustrated a forward-scattering peak over planar ice at low solar elevations. Afternoon measurements at the dirty ice site revealed the influence of surface metamorphosis. Hummocked ice and metamorphosed snow produced dominant backscattering peaks. The reasonably unresponsive temporal variation of glacier ice reflectivity is useful for satellite applications, as images obtained with a 6 hour window centred on solar noon are likely to be reliable within 2-3%.
Bibliography of Canadian Geomorphology