Satellite Remote Sensing of Glaciers and Ice Caps in Svalbard, Eurasian High Arctic

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Hamilton0221292Recent compilations of climate-related observations show that important changes are now underway in the High Arctic, probably as a response to anthropogenic greenhouse gas emissions over the last approximately 250 years. These changes include warming of the troposphere, reductions in sea ice cover, decreases in snow cover area, warming of tundra permafrost, and negative mass balances of glaciers and ice caps. In many instances, observations of change are relatively short in duration or sparse in spatial extent. The Principal Investigators will study glacier and ice cap variations over the approximately last 80 years and at a large scale on Svalbard. The islands contain the largest extent of glacier ice in northern Eurasia, amounting to about 0.03 meters of sea level equivalent water in storage. Measurements of glacier variations and mass balance have been conducted continuously on Svalbard since 1966, but most investigations are restricted to small glaciers in northwestern Svalbard. The behavior and current status of most large glaciers and ice caps is largely unknown. The work contained in this proposal involves using high resolution, modern satellite imagery to map current glacier and ice cap extents. These maps will be compared with archival information to assess rates and styles of change. The primary type of modern imagery to be used will be from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument carried onboard Terra. Archival sources of information include geodetic maps, Declassified Intelligence Satellite Photography (DISP) imagery and Landsat MSS (Multi-spectral Scanner) imagery. The overall aim of the proposed work is to understand the current mass balance of ice masses in Svalbard and their current and future contribution to sea level change. There are several objectives: 1) mapping modern boundaries of glaciers and ice caps in Svalbard using satellite imagery and comparing those with archival information to assess changes over a 50 or longer year period; 2) constructing time series of snow facies extent and late summer snowline positions using remotely sensed data to determine short- and medium-term variability; 3) mapping changes in ice flow to determine the importance of flow instabilities; 4) using observed changes to assess spatial variability in glacier and ice cap mass balance across the archipelago; and 5) interpreting the causes of observed changes.