Evaluating Models for Calculating Sub-Debris Ice Ablation

Abstract:

Debris-covered glaciers are a common feature of the mountain cryosphere, and the proportion of glacierized area that is debris-covered is increasing in many regions. Thus, in order to generate decadal or centennial projections of runoff and mass change of these glaciers it is important to be able to quantify the impact of surface debris on ice ablation.

While exposed ice cliffs, ponded water and fluvial action are all important contributors to ablation within debris-covered areas, the focus here is on assessing the performance of a number of models of sub-debris melt of varying complexity. The goal is to determine the impact simplifying assumptions can be expected to have on glacier ablation over seasonal, annual and decadal timescales.