SVALI post doc: 2013-2015
Subject: Measuring bare glacier ice impurity loading and parametrizing glacier ice albedo.
Theme 2: Understanding the physical processes
Work package 2.3: Integration of atmospheric, cryospheric and hydrological processes at glacier surfaces
Task 2.3b: Ice sheet surface albedo
Solar radiation is the major energy source for melt at a glacier's surface. The fraction of the incoming solar radiation that gets reflected by the ice is defined as the the surface albedo. The remaining part of the solar radiation is absorbed by the ice and thus surface albedo is of crucial importance to glacier melt. While the albedo of snow and the changes therein can be parametrized with relative ease, no parametrization exists to date for bare glacier ice. Addressing this gap in knowledge is essential for achieving more reliable scenarios of future glacier mass balance. We aim at improving the understanding of the controlling factors of bare glacier ice albedo and deriving a parametrization of the latter. A data set from different glaciers was collected including surface albedo and bare glacier ice impurity loading. This data set is used to derive relations which quantifies the albedo based on impurity concentrations. The possible causes for differences in albedo and impurity loading between different glacier types will also be analyzed. And, the final aim is to make the derived algorithms available for the modelling community in SVALI.