DIGITAL

Scientific publication

SMARAGD - Satellite Monitoring and Regional Analysis of Glacier Dynamics in the Barents-Kara Region

Publication from Digital

Dr Aleksey Sharov

, 1/2010

Abstract:

Original remote sensing studies using satellite photogrammetry, interferometry and altimetry will be carried out in order to determine the magnitude, character and main causes of glacier changes in the Franz Josef Land archipelago (FJL). The main emphasis will be put on studying dynamical processes related to ice flow, calving, snow accumulation, elevation changes and mass-balance fluctuations of large tidewater glaciers (TWGs) in response to climatic alterations. The key study area comprises
 several large ice caps and outlet glaciers draining ice into Austrian Channel in the central part of FJL.  An integral assessment of the extent and spatial changes of the FJL's glaciation in the course of the past 50 years will be performed by comparing available topographic maps and "old" glacier elevation models with up-to-date spaceborne image data and "new" elevation models featuring high ground resolution, good vertical accuracy and broad terrestrial coverage. Differential interferometric models of the study TWGs available since about the past decade will lay the groundwork for revealing and analyzing spatiotemporal variations in the glacier regime on a regional scale. Frontal glacier velocities will be measured from single tide-coordinated SAR interferograms using an original transferential approach based on the analysis of the fast-sea-ice translation away from the shore as a result of glacier motion. The differences in the glaciation status revealed between 1950s and 2000s will be expressed both in volumetric and fluxometric terms and represented in the most versatile and easily interpreted form of satellite image maps and animated evolution models. Straightforward and rigorous procedure will be developed for the generation and absolute
 orientation of glacier elevation & evolution models making use of spaceborne stereoscopic, interferometric, altimetric and gravimetric data and sensor-specific imaging models.  The analysis of geometric uncertainties persisting in remote sensing determinations will be performed; the "discoveries" / geographic findings gained in the laboratory by different techniques will be intrervalidated and compared with the results from field observations and those obtained by other investigators. A hypothesis of general thinning and decelerating of large TWGs in the Barents Sea region will be checked and a conjectural idea relating spatial asymmetry in snow accumulation, glacier extent, ice flow and sea ice phenology with the existence of gravity anomalies will be either verified or negated by means of multivariate data analysis and field surveys in 2007 - 08. It will be confirmed that the high glacier strain rates and surface roughness manifested in our phase-gradient interferometric models can reliably indicate faster changes in the glacier marginal areas in near-time projections.  The research is considered as a part of IPY initiatives and CalVal observations related with the launch and operation of the ESA GOCE (2007) and CryoSat-2 (2009) satellites. This is the first time that dynamic changes in glacier topography and rheology over the whole archipelago will be revealed, measured, explained, predicted and mapped within a single remote sensing study. The adequate understanding
 of interrelations between climate change and glacier dynamics in FJL, their potential impacts and illustrative scenarios of future changes will be communicated to scholars, students, teachers and policy makers.