Migration model establishment over Greenland Russell glacier with Remote Sensing observations and hydrodynamic simulations

Abstract:

The mechanism of arctic ice sheet migration is not yet fully identified. Glacial movement, specifically that involving supra/under glacial hydrological channel activities, may hold the key for understanding the acceleration of Greenland’s ice sheet change and needs to be investigated in depth and established as an integrated model. The test area on which the above studies were conducted was in the Russell glacier in western Greenland, where glacial change has been obvious for the last century and significant fluvial flows occur in meltwater outflow channels, such as the Akuliarusiarsuup Kuua and Qinnguata Kuussua rivers.

All tasks in the study were conducted in three stages: 1) collecting 3D migration vectors combining C and L band differential interferometric SAR (D-InSAR) analysis, together with the in-house pixel tracking method employing optical flow and sub-pixel refinement; 2) a 2D hydrodynamic simulation based on the channel bathymetry, which was driven from calibrated LANDSAT images together with along-track stereo DTM; and 3) the model inversion to extract the bedrock height and the physical processes under the glaciers. Throughout those approaches, the researchers intended to identify firstly the interconnected processes between subglacier melt water flow and glacial migration, and also the model establishments of the involved processes.

Consequently, the study revealed highly important clues about glacial migration. First of all, the importance of hydrological channel morphology as a governing factor over glaciers’ outflowed total melt water was identified. Also, it became clear that the reconstruction of sub glacial processes and morphology are feasible by employing remote sensing observations and model inversions. Those experiences will naturally lead to a more comprehensive understanding of the processes on the terminus of glacier.

The overall results from these approaches were compared and validated against published bedrock heights and ice thicknesses. Based on the output of this study, the proposed method will be extended to a scheme to tackle the issues of ice sheet change occurring in the Greenland costal area.