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Michele Citterio, GEUS - Geological Survey of Denmark and Greenland (Denmark)
Andreas P. Ahlstrøm, GEUS - Geological Survey of Denmark and Greenland (Denmark)
Robert S. Fausto, GEUS - Geological Survey of Denmark and Greenland (Denmark)
Charlotte Sigsgaard, University of Copenhagen (Denmark)
Mikkel P. Tamstorf, National Environmental Research Institute, University of Århus (Denmark)
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The Arctic is expected to undergo a marked warming in the coming decades, and a significant effort has been focused on collecting climate information on the Greenland ice sheet through the establishment of monitoring networks such as the US Greenland Climate Network (GC-Net), the Danish Programme for Monitoring of the Greenland Ice Sheet (PROMICE) and the Dutch Kangerlussuaq transect (K-transect). Recently, glaciers and ice caps have been identified as the major contributors of mass to sea-level rise in the 21st century. This outlook, and the present scarceness of field observations at glaciers and ice caps in Greenland, prompted the establishment of GlacioBasis, a new monitoring program started in 2008 and funded through the Dancea program at the Danish Ministry for Climate and Energy.
GlacioBasis will provide a continuous and consistent record of quantitative field observations at the A. P. Olsen Ice Cap (74.6° N, 21.5° W) and along the glacier tongue flowing down into the Zackenberg drainage basin. Two Automatic Weather Stations (AWS) at different altitudes in the ablation zone along the central flowline start operating in late March 2008. The main AWS will provide complete punctual energy balance, plus snow depth, ice ablation and GPS position. The main AWS can transmit quasi real-time data from the whole sensor suite to Copenhagen through an Iridium satellite link both during summertime and, at a reduced data rate, during wintertime. The second AWS collects a subset of parameters and provides the physical gradients needed for modelling. A third AWS will be set up in the accumulation zone during 2009. We give an overview of the AWS data that, after validation, will be made available to the scientific community.
GPS velocity surveys, ablation stake measurements and snow density from snow pits will be repeated every year, as well as GPR (Ground Penetrating Radar) surveys aimed at estimating the spatial variability of snow accumulation.
Ice thickness and bottom topography will be obtained either by airborne or ground based lower frequency GPR in the coming years, and ASTER imagery is being acquired through the GLIMS Project.
We present our results concerning the snow cover, and compare instrumentally measured ablation at the main AWS, simulated ablation and runoff from a distributed melt model, and observed river discharge.
GlacioBasis data complement the datasets produced by the other monitoring programs running in the area, such as gauge records of water discharge rates in the river system, snow cover outside of the glacierized area, and climatic data from the AWSs in the Zackenberg valley.
The IPY Overvintringsprojekt (ISICaB), supported by the Commission for Scientific Research in Greenland (KVUG), granted early access to the extensive facilities at the Zackenberg Research Station, owned by the Greenland Home Rule and operated by the Danish Polar Center, allowing GlacioBasis to be set up in the field well before the end of the accumulation season.
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