Decadal Survey of Supraglacial Debris Covers Over Arctic Svalbard Glaciers

Abstract:

Glacier mass equilibrium, Glacier stability, Glacier hydrology, Annual snow sheet growth, Snow and Atmospheric contact, Ice cores (Climate and Contaminant Studies) and Glacier biogeochemistry are important fields of study in Arctic glaciology. On the other hand, only a handful of studies have been carried out to understand the evolution and distribution of supraglacial debris cover in Arctic Svalbard glaciers. Supraglacial debris influences the ablation system of the underlying ice and the energy balance of the atmosphere. The present study focus on the supraglacial debris-cover (SDC) estimation of Austre Brøggerbreen and Vestre Brøggerbreen glaciers located in Ny-Ålesund. Ny- Ålesund located in Arctic Svalbard archipelago is well known for having diverse climatic conditions and an ideal site for glaciological research and monitoring. The study has been carried out for the period 2009-2019 using Landsat-7/8 datasets. The supraglacial debris has been mapped using the well-known NDSI and NIR/SWIR band ratio techniques which differentiate the supraglacial debris from the ice and snow in the glaciers by thresholding. Results indicate that on average, 7% and 10% of the glaciated area is covered with supraglacial debris cover for Austre Brøggerbreen and Vestre Brøggerbreen glaciers. The created SDC maps can be integrated into the mass balance models to forecast potential losses due to climate change. The proposed work has been validated by field visit to Arctic glacier which is first of its kind enhancing India’s scientific credentials in Polar research.