Instantaneous glacierization, the rate of albedo change, and feedback effects at the beginning of an ice age

Abstract

A study of the average annual- and melt-season albedos for the northwest side of the Devon Island Ice Cap shows that there is no step in the average albedo either at the equilibrium or firn line. Similarly, during a period of increasing glacierization there is nowhere any dramatic increase in the average annual- or melt-season albedo with time as the equilibrium line gradually moves downslope. This means that the inception of ice caps and permanent snowfields does not make a significant change to the rate of increasing albedo and its associated feedback effects during the same period of glacierization. The extension of the annual period of snowcover generally is much more important to the feedback process (by increasing albedo) than the specific lowering of the equilibrium line. A decreased variability of summer climate, and hence the disappearance of “anomalously” warm summers, may be an integral part of the glacierizing process.