C05 Impacts of Dust and Black Carbon on Snow and Glaciers

IACS (Cryosphere)

25-Jun-2015, 16:30 - 18:00

Abstract content:

Glacier mass balance modelling: Improvements using imaging spectroscopy derived ice surface material composition and spectral albedo

Glaciers are neither clean nor homogeneous. In fact, they represent diverse surfaces with different materials and structures. Although organisms living on ice surfaces, in-situ sampling of cryoconite and the use of local automatic weather stations to observe glacier surface albedo have received considerable interest, there is still only little known about the presence and distribution of light absorbing impurities on glacier surfaces and their impact on albedo and, hence, mass balance.

In this study, we apply an approach combining airborne and in-situ observations together with numerical models to characterize glacier surfaces, in particular the distribution of ice surface materials and their influence on glacier mass balance. The APEX (Airborne Prism EXperiment) image spectrometer was used to acquire spatial and spectral high resolution radiation measurements over Glacier de la Plaine Morte and Findelengletscher in the Swiss Alps. In-situ radiation measurements were acquired with an ASD field spectrometer. Further, data of seasonal glacier mass balance over the last five years is available to calibrate a distributed model for calculating glacier-wide surface mass balance.

We present results of surface classification including estimated abundances of different materials and derive spectral albedo maps representing the spatial variability in ice surface albedo. Furthermore, we demonstrate the added value of using actual ice surface albedo information for reproducing observed melt rates, by implementing such data products into a distributed mass balance model.
Our results contribute to a better understanding of the spatial distribution of glacier melt, which is important to improve models to study future glacier evolution.

K. Naegeli1, A. Damm2, M. Huss1,3, M. Schaepman2, M. Hoelzle1.
1University of Fribourg, Department of Geosciences, Fribourg, Switzerland.
2University of Zurich, Remote Sensing Laboratories, Zurich, Switzerland.


glacier     albedo     cryoconite     mass balance     imaging spectroscopy     remote sensing