CGRG Bibliography of Canadian Geomorphology
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Author : Arendt, A.
Date : 1999.
Title : Approaches to modelling the surface albedo of a high Arctic glacier.
Publication : Geografiska Annaler
Issue : 81A(4):
Page(s) : 477-487.
Abstract
Broadband surface albedo measurements, made during the summer melt season at three weather stations on John Evans Glacier (79 degrees 40'N, 74 degrees 00'W), varied strongly with the solar zenith angle (theta(z)). Tests were carried out to assess the impact of diurnal variations in surface albedo on seasonal net shortwave radiation (K*) totals. Removing the diurnal signal from albedo measurements by daily averaging of hourly measurements, or by applying midday measurements to all hours of the day, changed K* by up to 16%. Ignoring measurements made at theta(z) > 75 degrees, to account for measurement (cosine) error at high theta(z), decreased K* by between 5 and 18%. Given the sensitivity of K* to diurnal patterns in surface albedo, experiments were carried our with two albedo models. One model accounted for albedo variations with theta(z) and one did not. The model driven by theta(z), when implemented within a surface energy balance model for John Evans Glacier, produced better melt estimates. This suggests that diurnal variations in surface albedo should be accounted for in energy balance models of glacier melt.
Bibliography of Canadian Geomorphology